String and type wrappers

String in Java is a?

• class

• object

• variable

• character array

Which of these method of String class can be used to test to strings for equality?

• isequal()

• isequals()

• equal()

• equals()

Which of the following statements are incorrect?

• String is a class

• Strings in java are mutable

• Every string is an object of class String

• Java defines a peer class of String, called StringBuffer, which allows string to be altered

What will be the output of the following Java program?

class string_demo

{

public static void main(String args[])

{

String obj = "I" + "like" + "Java";

System.out.println(obj);

}

}

• I

• like

• Java

• IlikeJava

What will be the output of the following Java program?

class output

{

public static void main(String args[])

{

StringBuffer s1 = new StringBuffer("Hello");

StringBuffer s2 = s1.reverse();

System.out.println(s2);

}

}

• Hello

• olleH

• HelloolleH

• olleHHello

What will be the output of the following Java program?

class output

{

public static void main(String args[])

{

StringBuffer c = new StringBuffer("Hello");

c.delete(0,2);

System.out.println(c);

}

}

• He

• Hel

• lo

• llo

Which of these method of class StringBuffer is used to find the length of current character sequence?

• length()

• Length()

• capacity()

• Capacity()

Which of this method of class StringBuilder is used to concatenate the string representation to the end of invoking string?

• concat()

• append()

• join()

• concatenate()

Which of the following is method of wrapper Integer for converting the value of an object into int?

• bytevalue()

• int intValue();

• Bytevalue()

• Byte Bytevalue()

What will be the output of the following Java program?

1. class Output

2. {

3. public static void main(String args[])

4. {

5. Integer i = new Integer(257);

6. byte x = i.byteValue();

7. System.out.print(x);

8. }

9. }

• 0

• 256

• 1

• 257