{"id":138,"date":"2020-04-03T08:59:10","date_gmt":"2020-04-03T08:59:10","guid":{"rendered":"https:\/\/temp.ashkerala.com\/?p=138"},"modified":"2020-04-03T08:59:10","modified_gmt":"2020-04-03T08:59:10","slug":"java-packages","status":"publish","type":"post","link":"https:\/\/temp.ashkerala.com\/?p=138","title":{"rendered":"Java Packages"},"content":{"rendered":"

Java.lang<\/strong><\/p>\n

\u00a0\u00a0\u00a0 1) java.lang package is automatically imported into all programs.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a<\/p>\n

\u00a0\u00a0\u00a0 2) What are the interfaces defined by java.lang?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Cloneable, Comparable and Runnable.<\/p>\n

\u00a0\u00a0\u00a0 3) What are the constants defined by both Flaot and Double classes?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : MAX_VALUE,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MIN_VALUE,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NaN ,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 POSITIVE_INFINITY,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 NEGATIVE_INFINITY and<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 TYPE.<\/p>\n

\u00a0\u00a0\u00a0 4) What are the constants defined by Byte, Short, Integer and Long?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : MAX_VALUE,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MIN_VALUE and<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 TYPE.<\/p>\n

\u00a0\u00a0\u00a0 5) What are the constants defined by both Float and Double classes?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : MAX_RADIX,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MIN_RADIX,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MAX_VALUE,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MIN_VALUE and<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 TYPE.<\/p>\n

\u00a0\u00a0\u00a0 6) What is the purpose of the Runtime class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The purpose of the Runtime class is to provide access to the Java runtime system.<\/p>\n

\u00a0\u00a0\u00a0 7) What is the purpose of the System class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The purpose of the System class is to provide access to system resources.<\/p>\n

\u00a0\u00a0\u00a0 8) Which class is extended by all other classes?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Object class is extended by all other classes.<\/p>\n

\u00a0\u00a0\u00a0 9) Which class can be used to obtain design information about an object?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The Class class can be used to obtain information about an object\u0393\u00c7\u00d6s design.<\/p>\n

\u00a0\u00a0\u00a0 10) Which method is used to calculate the absolute value of a number?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : abs( ) method.<\/p>\n

\u00a0\u00a0\u00a0 11) What are E and PI?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : E is the base of the natural logarithm and PI is the mathematical value pi.<\/p>\n

\u00a0\u00a0\u00a0 12) Which of the following classes is used to perform basic console I\/O?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 SecurityManager
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Math
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Runtime<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 13) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Class class is the superclass of the Object class.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Object class is final.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Class class can be used to load other classes.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The ClassLoader class can be used to load other classes.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c and d.<\/p>\n

\u00a0\u00a0\u00a0 14) Which of the following methods are methods of the Math class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 absolute( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 log( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 cosine( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 sine( )<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 15) Which of the following are true about the Error and Exception classes?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Both classes extend Throwable.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Error class is final and the Exception class is not.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Exception class is final and the Error is not.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Both classes implement Throwable.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 16) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Void class extends the Class class.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Float class extends the Double class.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The System class extends the Runtime class.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Integer class extends the Number class.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : d.<\/p>\n

\u00a0\u00a0\u00a0 17) Which of the following will output -4.0<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(Math.floor(-4.7));
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(Math.round(-4.7));
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(Math.ceil(-4.7));
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(Math.Min(-4.7));<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

\u00a0\u00a0\u00a0 18) Which of the following are valid statements<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) public class MyCalc extends Math
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) Math.max(s);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) Math.round(9.99,1);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) Math.mod(4,10);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 e) None of the above.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : e.<\/p>\n

\u00a0\u00a0\u00a0 19) What will happen if you attempt to compile and run the following code?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Integer ten=new Integer(10);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Long nine=new Long (9);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(ten + nine);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 int i=1;<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 System.out.println(i + ten);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 19 followed by 20
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 19 followed by 11
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Error: Can’t convert java lang Integer<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) 10 followed by 1<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

Input\/Output<\/strong><\/p>\n

\u00a0\u00a0\u00a0 1) What is meant by Stream and what are the types of Streams and classes of the Streams?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : A Stream is an abstraction that either produces or consumes information.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 There are two types of Streams. They are:<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Byte Streams : Byte Streams provide a convenient means for handling input and output of bytes.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Character Streams : Character Streams provide a convenient means for handling input and output of characters.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Byte Stream classes : Byte Streams are defined by using two abstract classes. They are:InputStream and OutputStream.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Character Stream classes : Character Streams are defined by using two abstract classes. They are : Reader and Writer.<\/p>\n

\u00a0\u00a0\u00a0 2) Which of the following statements are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 UTF characters are all 8-bits.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 UTF characters are all 16-bits.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 UTF characters are all 24-bits.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Unicode characters are all 16-bits.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Bytecode characters are all 16-bits.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : d.<\/p>\n

\u00a0\u00a0\u00a0 3) Which of the following statements are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 When you construct an instance of File, if you do not use the filenaming semantics of the local machine, the constructor will throw an IOException.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 When you construct an instance of File, if the corresponding file does not exist on the local file system, one will be created.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 When an instance of File is garbage collected, the corresponding file on the local file system is deleted.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 None of the above.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a,b and c.<\/p>\n

\u00a0\u00a0\u00a0 4) The File class contains a method that changes the current working directory.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 5) It is possible to use the File class to list the contents of the current working directory.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 6) Readers have methods that can read and return floats and doubles.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 7) You execute the code below in an empty directory. What is the result?<\/p>\n

\u00a0\u00a0\u00a0 File f1 = new File(“dirname”);<\/p>\n

\u00a0\u00a0\u00a0 File f2 = new File(f1, “filename”);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A new directory called dirname is created in the current working directory.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A new directory called dirname is created in the current working directory. A new file called filename is created in directory dirname.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A new directory called dirname and a new file called filename are created, both in the current working directory.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A new file called filename is created in the current working directory.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 No directory is created, and no file is created.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : e.<\/p>\n

\u00a0\u00a0\u00a0 8) What is the difference between the Reader\/Writer class hierarchy and the InputStream\/OutputStream class hierarchy?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The Reader\/Writer class hierarchy is character-oriented and the InputStream\/OutputStream class hierarchy is byte-oriented.<\/p>\n

\u00a0\u00a0\u00a0 9) What is an I\/O filter?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : An I\/O filter is an object that reads from one stream and writes to another, usually altering the data in some way as it is passed from one stream to another.<\/p>\n

\u00a0\u00a0\u00a0 10) What is the purpose of the File class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The File class is used to create objects that provide access to the files and directories of a local file system.<\/p>\n

\u00a0\u00a0\u00a0 11) What interface must an object implement before it can be written to a stream as an object?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : An object must implement the Serializable or Externalizable interface before it can be written to a stream as an object.<\/p>\n

\u00a0\u00a0\u00a0 12) What is the difference between the File and RandomAccessFile classes?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The File class encapsulates the files and directories of the local file system. The RandomAccessFile class provides the methods needed to directly access data contained in any part of a file.<\/p>\n

\u00a0\u00a0\u00a0 13) What class allows you to read objects directly from a stream?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The ObjectInputStream class supports the reading of objects from input streams.<\/p>\n

\u00a0\u00a0\u00a0 14) What value does read( ) return when it has reached the end of a file?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The read( ) method returns \u0393\u00c7\u00f4 1 when it has reached the end of a file.<\/p>\n

\u00a0\u00a0\u00a0 15) What value does readLine( ) return when it has reached the end of a file?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The readLine( ) method returns null when it has reached the end of a file.<\/p>\n

\u00a0\u00a0\u00a0 16) How many bits are used to represent Unicode, ASCII, UTF-16 and UTF-8 characters?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Unicode requires 16-bits and ASCII requires 8-bits. Although the ASCII character set uses only 1-bits, it is usually represented as 8-bits. UTF-8 represents characters using 8, 16 and 18-bit patterns. UTF-16 uses 16-bit and larger bit patterns.<\/p>\n

\u00a0\u00a0\u00a0 17) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The InputStream and OutputStream classes are byte-oriented.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The ObjectInputStream and ObjectOutputStream do not support serialized object input and output.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Reader and Writer classes are character-oriented.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Reader and Writer classes are the preferred solution to serialized object output.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and c.<\/p>\n

\u00a0\u00a0\u00a0 18) Which of the following are true about I\/O filters?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Filters are supported on input, but not on output.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Filters are supported by the InputStream\/OutputStream class hierarchy, but not by the Reader\/Writer class hierarchy.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Filters read from one stream and write to another.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A filter may alter data that is read from one stream and written to another.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c and d.<\/p>\n

\u00a0\u00a0\u00a0 19) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Any Unicode character is represented using 16-bits.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 7-bits are needed to represent any ASCII character.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 UTF-8 characters are represented using only 8-bits.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 UTF-16 characters are represented using only 16-bits.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and b.<\/p>\n

\u00a0\u00a0\u00a0 20) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Serializable interface is used to identify objects that may be written to an output stream.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Externalizable interface is implemented by classes that control the way in which their objects are serialized.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Serializable interface extends the Externalizable interface.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The Externalizable interface extends the Serializable interface.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a, b and d.<\/p>\n

\u00a0\u00a0\u00a0 21) Which of the following are true about the File class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A File object can be used to change the current working directory.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A File object can be used to access the files in the current directory.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 When a File object is created, a corresponding directory or file is created in the local file system.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 File objects are used to access files and directories on the local file system.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 File objects can be garbage collected.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 When a File object is garbage collected, the corresponding file or directory is deleted.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b, d and e.<\/p>\n

\u00a0\u00a0\u00a0 22) How do you create a Reader object from an InputStream object?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Use the static createReader( ) method of InputStream class.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Use the static createReader( ) method of Reader class.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Create an InputStreamReader object, passing the InputStream object as an argument to the InputStreamReader constructor.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Create an OutputStreamReader object, passing the InputStream object as an argument to the OutputStreamReader constructor.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

\u00a0\u00a0\u00a0 23) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Writer classes can be used to write characters to output streams using different character encodings.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Writer classes can be used to write Unicode characters to output streams.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Writer classes have methods that support the writing of the values of any Java primitive type to output streams.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Writer classes have methods that support the writing of objects to output streams.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and b.<\/p>\n

\u00a0\u00a0\u00a0 24) The isFile( ) method returns a boolean value depending on whether the file object is a file or a directory.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 25) Reading or writing can be done even after closing the input\/output source.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 26) The ________ method helps in clearing the buffer.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : flush( ).<\/p>\n

\u00a0\u00a0\u00a0 27) The System.err method is used to print error message.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 28) What is meant by StreamTokenizer?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : StreamTokenizer breaks up InputStream into tokens that are delimited by sets of characters.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 It has the constructor : StreamTokenizer(Reader inStream).<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Here inStream must be some form of Reader.<\/p>\n

\u00a0\u00a0\u00a0 29) What is Serialization and deserialization?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Serialization is the process of writing the state of an object to a byte stream.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Deserialization is the process of restoring these objects.<\/p>\n

\u00a0\u00a0\u00a0 30) Which of the following can you perform using the File class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) Change the current directory
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) Return the name of the parent directory
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) Delete a file
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) Find if a file contains text or binary information<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b and c.<\/p>\n

\u00a0\u00a0\u00a0 31) How can you change the current working directory using an instance of the File class called FileName?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FileName.chdir(“DirName”).
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FileName.cd(“DirName”).
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FileName.cwd(“DirName”).
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The File class does not support directly changing the current directory.<\/p>\n

\u00a0\u00a0\u00a0\u00a0 Ans : d.<\/p>\n

Applets<\/strong><\/p>\n

\u00a0\u00a0\u00a0 1) What is an Applet? Should applets have constructors?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Applet is a dynamic and interactive program that runs inside a Web page displayed by a Java capable browser. We don\u0393\u00c7\u00d6t have the concept of Constructors in Applets.<\/p>\n

\u00a0\u00a0\u00a0 2) How do we read number information from my applet\u0393\u00c7\u00d6s parameters, given that Applet\u0393\u00c7\u00d6s getParameter() method returns a string?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Use the parseInt() method in the Integer Class, the Float(String) constructor in the Class Float, or the Double(String) constructor in the class Double.<\/p>\n

\u00a0\u00a0\u00a0 3) How can I arrange for different applets on a web page to communicate with each other?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Name your applets inside the Applet tag and invoke AppletContext\u0393\u00c7\u00d6s getApplet() method in your applet code to obtain references to the other applets on the page.<\/p>\n

\u00a0\u00a0\u00a0 4) How do I select a URL from my Applet and send the browser to that page?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Ask the applet for its applet context and invoke showDocument() on that context object.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Eg. URL targetURL;<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 String URLString<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 AppletContext context = getAppletContext();<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 try{<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 targetUR L = new URL(URLString);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 } catch (Malformed URLException e){<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \/\/ Code for recover from the exception<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 context. showDocument (targetURL);<\/p>\n

\u00a0\u00a0\u00a0 5) Can applets on different pages communicate with each other?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : No. Not Directly. The applets will exchange the information at one meeting place<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 either on the local file system or at remote system.<\/p>\n

\u00a0\u00a0\u00a0 6) How do Applets differ from Applications?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Appln: Stand Alone<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Applet: Needs no explicit installation on local m\/c.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Appln: Execution starts with main() method.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Applet: Execution starts with init() method.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Appln: May or may not be a GUI<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Applet: Must run within a GUI (Using AWT)<\/p>\n

\u00a0\u00a0\u00a0 7) How do I determine the width and height of my application?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Use the getSize() method, which the Applet class inherits from the Component<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 class in the Java.awt package. The getSize() method returns the size of the applet as<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a Dimension object, from which you extract separate width, height fields.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Eg. Dimension dim = getSize ();<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 int appletwidth = dim.width ();<\/p>\n

\u00a0\u00a0\u00a0 8) What is AppletStub Interface?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The applet stub interface provides the means by which an applet and the browser communicate. Your code will not typically implement this interface.<\/p>\n

\u00a0\u00a0\u00a0 9) It is essential to have both the .java file and the .html file of an applet in the same directory.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : 2.<\/p>\n

\u00a0\u00a0\u00a0 10) The <PARAM> tag contains two attributes namely _________ and _______.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Name , value.<\/p>\n

\u00a0\u00a0\u00a0 11) Passing values to parameters is done in the _________ file of an applet.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : .html.<\/p>\n

\u00a0\u00a0\u00a0 12) What tags are mandatory when creating HTML to display an applet<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 name, height, width
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 code, name
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 codebase, height, width
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 code, height, width<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : 4.<\/p>\n

\u00a0\u00a0\u00a0 13) Applet\u0393\u00c7\u00d6s getParameter( ) method can be used to get parameter values.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 14) What are the Applet\u0393\u00c7\u00d6s Life Cycle methods? Explain them?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : init( ) method – Can be called when an applet is first loaded.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 start( ) method – Can be called each time an applet is started.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 paint( ) method – Can be called when the applet is minimized or refreshed.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 stop( ) method – Can be called when the browser moves off the applet\u0393\u00c7\u00d6s page.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destroy( ) method – Can be called when the browser is finished with the applet.<\/p>\n

\u00a0\u00a0\u00a0 15) What are the Applet\u0393\u00c7\u00d6s information methods?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : getAppletInfo( ) method : Returns a string describing the applet, its author ,copy<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 right information, etc.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 getParameterInfo( ) method : Returns an array of string describing the applet\u0393\u00c7\u00d6s parameters.<\/p>\n

\u00a0\u00a0\u00a0 16) All Applets are subclasses of Applet.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 17) All Applets must import java.applet and java.awt.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 18) What are the steps involved in Applet development?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a) Edit a Java source file,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) Compile your program and<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) Execute the appletviewer, specifying the name of your applet\u0393\u00c7\u00d6s source file.<\/p>\n

\u00a0\u00a0\u00a0 19) Applets are executed by the console based Java run-time interpreter.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 20) Which classes and interfaces does Applet class consist?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Applet class consists of a single class, the Applet class and three interfaces: AppletContext,<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 AppletStub and AudioClip.<\/p>\n

\u00a0\u00a0\u00a0 21) What is the sequence for calling the methods by AWT for applets?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : When an applet begins, the AWT calls the following methods, in this sequence.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 init( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 start( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 paint( )<\/p>\n

\u00a0\u00a0\u00a0 22) When an applet is terminated, the following sequence of method cals takes place :<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 stop( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 destroy( )<\/p>\n

\u00a0\u00a0\u00a0 23) Which method is used to output a string to an applet?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : drawString ( ) method.<\/p>\n

\u00a0\u00a0\u00a0 24) Every color is created from an RGB value.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.\u00a0<\/p>\n

Event Handling<\/strong><\/p>\n

\u00a0\u00a0\u00a0 1) The event delegation model, introduced in release 1.1 of the JDK, is fully compatible with the event model.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 2) A component subclass that has executed enableEvents( ) to enable processing of a certain kind of event cannot also use an adapter as a listener for the same kind of event.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 3) What is the highest-level event class of the event-delegation model?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The java.util.eventObject class is the highest-level class in the event-delegation hierarchy.<\/p>\n

\u00a0\u00a0\u00a0 4) What interface is extended by AWT event listeners?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : All AWT event listeners extend the java.util.EventListener interface.<\/p>\n

\u00a0\u00a0\u00a0 5) What class is the top of the AWT event hierarchy?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The java.awt.AWTEvent class is the highest-level class in the AWT event class hierarchy.<\/p>\n

\u00a0\u00a0\u00a0 6) What event results from the clicking of a button?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The ActionEvent event is generated as the result of the clicking of a button.<\/p>\n

\u00a0\u00a0\u00a0 7) What is the relationship between an event-listener interface and an event-adapter class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : An event-listener interface defines the methods that must be implemented by an event handler for a particular kind of event. An event adapter provides a default implementation of an event-listener interface.<\/p>\n

\u00a0\u00a0\u00a0 8) In which package are most of the AWT events that support the event-delegation model defined?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Most of the AWT\u0393\u00c7\u00f4related events of the event-delegation model are defined in the java.awt.event package. The AWTEvent class is defined in the java.awt package.<\/p>\n

\u00a0\u00a0\u00a0 9) What is the advantage of the event-delegation model over the earlier event-inheritance model?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The event-delegation has two advantages over the event-inheritance model. They are :<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 It enables event handling by objects other than the ones that generate the events. This allows a clean separation between a component\u0393\u00c7\u00d6s design and its use.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 It performs much better in applications where many events are generated. This performance improvement is due to the fact that the event-delegation model does not have to repeatedly process unhandled events, as is the case of the event-inheritance model.<\/p>\n

\u00a0\u00a0\u00a0 10) What is the purpose of the enableEvents( ) method?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans :The enableEvents( ) method is used to enable an event for a particular object.<\/p>\n

\u00a0\u00a0\u00a0 11) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The event-inheritance model has replaced the event-delegation model.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The event-inheritance model is more efficient than the event-delegation model.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The event-delegation model uses event listeners to define the methods of event-handling classes.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The event-delegation model uses the handleEvent( ) method to support event handling.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

\u00a0\u00a0\u00a0 12) Which of the following is the highest class in the event-delegation model?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 java.util.EventListener
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 java.util.EventObject
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 java.awt.AWTEvent
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 java.awt.event.AWTEvent<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 13) When two or more objects are added as listeners for the same event, which listener is first invoked to handle the event?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The first object that was added as listener.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The last object that was added as listener.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 There is no way to determine which listener will be invoked first.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 It is impossible to have more than one listener for a given event.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

\u00a0\u00a0\u00a0 14) Which of the following components generate action events?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Buttons
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Labels
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Check boxes
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Windows<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 15) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A TextField object may generate an ActionEvent.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A TextArea object may generate an ActionEvent.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A Button object may generate an ActionEvent.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A MenuItem object may generate an ActionEvent.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a,c and d.<\/p>\n

\u00a0\u00a0\u00a0 16) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The MouseListener interface defines methods for handling mouse clicks.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The MouseMotionListener interface defines methods for handling mouse clicks.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The MouseClickListener interface defines methods for handling mouse clicks.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The ActionListener interface defines methods for handling the clicking of a button.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and d.<\/p>\n

\u00a0\u00a0\u00a0 17) Suppose that you want to have an object eh handle the TextEvent of a TextArea object t. How should you add eh as the event handler for t?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 t.addTextListener(eh);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 eh.addTextListener(t);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 addTextListener(eh.t);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 addTextListener(t,eh);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 18) What is the preferred way to handle an object\u0393\u00c7\u00d6s events in Java 2?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Override the object\u0393\u00c7\u00d6s handleEvent( ) method.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Add one or more event listeners to handle the events.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Have the object override its processEvent( ) methods.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Have the object override its dispatchEvent( ) methods.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 19) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A component may handle its own events by adding itself as an event listener.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A component may handle its own events by overriding its event-dispatching method.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A component may not handle oits own events.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A component may handle its own events only if it implements the handleEvent( ) method.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and b.<\/p>\n

\u00a0\u00a0\u00a0 20) How many types of events are provided by AWT? Explain them?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The AWT provides two types of events. They are :<\/p>\n

\u00a0\u00a0\u00a0 21) Low-level event : A low-level event is the one that represents a low-level input or window-system occurrence on a visual component on the screen.<\/p>\n

\u00a0\u00a0\u00a0 22) Semantic event : Semantic event is defined at a higher-level to encapsulate the semantics of a user interface component\u0393\u00c7\u00d6s model.<\/p>\n

\u00a0\u00a0\u00a0 23) A __________ is an object that originates or “fire” events.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : source.<\/p>\n

\u00a0\u00a0\u00a0 24) The event listener corresponding to handling keyboard events is the _________ .<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : KeyListener.<\/p>\n

\u00a0\u00a0\u00a0 25) What are the types of mouse event listeners?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : MouseListener and MouseMotionListener.<\/p>\n

\u00a0\u00a0\u00a0 26) Which of the following are correct event handling methods<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) mousePressed(MouseEvent e){}
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) MousePressed(MouseClick e){}
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) functionKey(KeyPress k){}
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) componentAdded(ContainerEvent e){}<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and d.<\/p>\n

\u00a0\u00a0\u00a0 27) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) A component may have only one event listener attached at a time
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) An event listener may be removed from a component
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) The ActionListener interface has no corresponding Adapter class
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) The processing of an event listener requires a try\/catch block<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b and c.<\/p>\n

\u00a0AWT : windows, graphics and fonts<\/strong><\/p>\n

\u00a0\u00a0\u00a0 1) How would you set the color of a graphics context called g to cyan?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(Color.cyan);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setCurrentColor(cyan);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(“Color.cyan”);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(“cyan\u0393\u00c7\u00d6);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(new Color(cyan));<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 2) The code below draws a line. What color is the line?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(Color.red.green.yellow.red.cyan);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.drawLine(0, 0, 100,100);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Red
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Green
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Yellow
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Cyan
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Black<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : d.<\/p>\n

\u00a0\u00a0\u00a0 3) What does the following code draw?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(Color.black);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.drawLine(10, 10, 10, 50);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.setColor(Color.RED);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.drawRect(100, 100, 150, 150);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A red vertical line that is 40 pixels long and a red square with sides of 150 pixels
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A black vertical line that is 40 pixels long and a red square with sides of 150 pixels
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A black vertical line that is 50 pixels long and a red square with sides of 150 pixels
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A red vertical line that is 50 pixels long and a red square with sides of 150 pixels
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A black vertical line that is 40 pixels long and a red square with sides of 100 pixel<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 4) Which of the statements below are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) A polyline is always filled.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) A polyline can not be filled.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) A polygon is always filled.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) A polygon is always closed<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 e) A polygon may be filled or not filled<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b, d and e.<\/p>\n

\u00a0\u00a0\u00a0 5) What code would you use to construct a 24-point bold serif font?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 new Font(Font.SERIF, 24,Font.BOLD);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 new Font(“SERIF”, 24, BOLD”);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 new Font(“BOLD “, 24,Font.SERIF);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 new Font(“SERIF”, Font.BOLD,24);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 new Font(Font.SERIF, “BOLD”, 24);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : 4.<\/p>\n

\u00a0\u00a0\u00a0 6) What does the following paint( ) method draw?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Public void paint(Graphics g) {<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.drawString(“question #6”,10,0);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The string “question #6”, with its top-left corner at 10,0
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A little squiggle coming down from the top of the component, a little way in from the left edge<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : 2.<\/p>\n

\u00a0\u00a0\u00a0 7) What does the following paint( ) method draw?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Public void paint(Graphics g) {<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 g.drawString(“question #6”,10,0);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 }<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A circle at (100, 100) with radius of 44
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A circle at (100, 44) with radius of 100
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A circle at (100, 44) with radius of 44
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The code does not compile<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : 4.<\/p>\n

\u00a0\u00a0\u00a0 8) What is relationship between the Canvas class and the Graphics class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : A Canvas object provides access to a Graphics object via its paint( ) method.<\/p>\n

\u00a0\u00a0\u00a0 9) What are the Component subclasses that support painting.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The Canvas, Frame, Panel and Applet classes support painting.<\/p>\n

\u00a0\u00a0\u00a0 10) What is the difference between the paint( ) and repaint( ) method?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The paint( ) method supports painting via a Graphics object. The repaint( ) method is used to cause paint( ) to be invoked by the AWT painting method.<\/p>\n

\u00a0\u00a0\u00a0 11) What is the difference between the Font and FontMetrics classes?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : The FontMetrics class is used to define implementation-specific properties, such as ascent and descent, of a Font object.<\/p>\n

\u00a0\u00a0\u00a0 12) Which of the following are passed as an argument to the paint( ) method?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A Canvas object
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A Graphics object
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 An Image object
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 A paint object<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : b.<\/p>\n

\u00a0\u00a0\u00a0 13) Which of the following methods are invoked by the AWT to support paint and repaint operations?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 paint( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 repaint( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 draw( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 redraw( )<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.<\/p>\n

\u00a0\u00a0\u00a0 14) Which of the following classes have a paint( ) method?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Canvas
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Image
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Frame
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Graphics<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and c.<\/p>\n

\u00a0\u00a0\u00a0 15) Which of the following are methods of the Graphics class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 drawRect( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 drawImage( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 drawPoint( )
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 drawString( )<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a, b and d.<\/p>\n

\u00a0\u00a0\u00a0 16) Which Font attributes are available through the FontMetrics class?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ascent
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 leading
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 case
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 height<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a, b and d.<\/p>\n

\u00a0\u00a0\u00a0 17) Which of the following are true?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The AWT automatically causes a window to be repainted when a portion of a window has been minimized and then maximized.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The AWT automatically causes a window to be repainted when a portion of a window has been covered and then uncovered.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The AWT automatically causes a window to be repainted when application data is changed.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 The AWT does not support repainting operations.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a and b.<\/p>\n

\u00a0\u00a0\u00a0 18) Which method is used to size a graphics object to fit the current size of the window?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : getSize( ) method.<\/p>\n

\u00a0\u00a0\u00a0 19) What are the methods to be used to set foreground and background colors?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : setForeground( ) and setBackground( ) methods.<\/p>\n

\u00a0\u00a0\u00a0 20) You have created a simple Frame and overridden the paint method as follows<\/p>\n

\u00a0\u00a0\u00a0 public void paint(Graphics g){<\/p>\n

\u00a0\u00a0\u00a0 \u00a0<\/p>\n

\u00a0\u00a0\u00a0 g.drawString(“Dolly”,50,10);<\/p>\n

\u00a0\u00a0\u00a0 \u00a0<\/p>\n

\u00a0\u00a0\u00a0 }<\/p>\n

\u00a0\u00a0\u00a0 What will be the result when you attempt to compile and run the program?<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) The string “Dolly” will be displayed at the centre of the frame<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) An error at compilation complaining at the signature of the paint method
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) The lower part of the word Dolly will be seen at the top of the form, with the top hidden.
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) The string “Dolly” will be shown at the bottom of the form<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

\u00a0\u00a0\u00a0 21) Where g is a graphics instance what will the following code draw on the screen.<\/p>\n

\u00a0\u00a0\u00a0 g.fillArc(45,90,50,50,90,180);<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a) An arc bounded by a box of height 45, width 90 with a centre point of 50,50, starting
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 at an angle of 90 degrees traversing through 180 degrees counter clockwise.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b) An arc bounded by a box of height 50, width 50, with a centre point of 45,90 starting
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 at an angle of 90 degrees traversing through 180 degrees clockwise.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c) An arc bounded by a box of height 50, width 50, with a top left at coordinates of 45,
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 90, starting at 90 degrees and traversing through 180 degrees counter clockwise.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d) An arc starting at 45 degrees, traversing through 90 degrees clockwise bounded by a
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 box of height 50, width 50 with a centre point of 90, 180.<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : c.<\/p>\n

\u00a0\u00a0\u00a0 22) Given the following code
\u00a0\u00a0\u00a0 import java.awt.*;
\u00a0\u00a0\u00a0 public class SetF extends Frame{
\u00a0\u00a0\u00a0 public static void main(String argv[]){
\u00a0\u00a0\u00a0 SetF s = new SetF();
\u00a0\u00a0\u00a0 s.setSize(300,200);
\u00a0\u00a0\u00a0 s.setVisible(true);
\u00a0\u00a0\u00a0 }
\u00a0\u00a0\u00a0 }
\u00a0\u00a0\u00a0 How could you set the frame surface color to pink<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 a)s.setBackground(Color.pink);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 b)s.setColor(PINK);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 c)s.Background(pink);
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 d)s.color=Color.pink<\/p>\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a.\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

Java.lang \u00a0\u00a0\u00a0 1) java.lang package is automatically imported into all programs. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 True \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 False \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : a \u00a0\u00a0\u00a0 2) What are the interfaces defined by java.lang? \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : Cloneable, Comparable and Runnable. \u00a0\u00a0\u00a0 3) What are the constants defined by both Flaot and Double classes? \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Ans : MAX_VALUE, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 MIN_VALUE, \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[12],"tags":[],"class_list":["post-138","post","type-post","status-publish","format-standard","hentry","category-java-programming"],"_links":{"self":[{"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=\/wp\/v2\/posts\/138","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=138"}],"version-history":[{"count":0,"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=\/wp\/v2\/posts\/138\/revisions"}],"wp:attachment":[{"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=138"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=138"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/temp.ashkerala.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=138"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}