String programing interview questions

1. what is the output of following program:

1. package com.instanceofjavaforus;
2.  
3. public class StringDemo{
4.  
5.  public static void main(String[] args) {
6.  
7.       String str="I love java";
8.       System.out.println(str.charAt(3));
9. }
10. }

1. o

2. what is the output of following program:

1. package com.instanceofjavaforus;
2.  
3. public class StringDemo{
4.  
5.  public static void main(String[] args) {
6.  
7.       String str="I love java";
8.       System.out.println(str.length());
9. }
10. }

1. 11

3. what is the output of following program:

1. package com.instanceofjavaforus;
2.  
3. public class StringDemo{
4.  
5.  public static void main(String[] args) {
6.  
7.       String str1="abc";
8.       String str2="abc";
9.  
10.        System.out.println(str1.equals(str2));
11. }
12. }

1. true

4. what is the output of following program:

1. package com.instanceofjavaforus;
2.  
3. public class StringDemo{
4.  
5.  public static void main(String[] args) {
6.  
7.         String str1 = "abc";
8.         String str2 = "abc";
9.         String str3= new String("abc");
10.  
11.         System.out.println("str1 == str2 ? "+(str1==str2));
12.         System.out.println("str1 == str3 ? "+(str1==str3));
13.         System.out.println("str1 equals str3 ? "+(str1.equals(str3)));
14.  
15.  
16. }
17. }

1. str1 == str2 ? true
2. str1 == str3 ? false
3. str1 equals str3 ? true