Given the code

String s1 = "yes" ;
String s2 = "yes" ;
String s3 = new String(s1) ;

Which of the following would equate to False ?

1. s1 == s2
2. s3 == s1
3. s1.equals(s2)
4. s3.equals(s1)

Suppose that s1 and s2 are two strings. Which of the statements or expressions are incorrect ?

1. String s3 = s1 + s2;
2. String s3 = s1 - s2;
3. s1.compareTo(s2);
4. int m = s1.length( );

Which of these class is superclass of String and StringBuffer class?

1. java.util
2. java.lang
3. ArrayList
4. None of the mentioned

Which of these methods of class String is used to obtain length of String object?

1. get( )
2. Sizeof( )
3. lengthof( )
4. length( )