Given:

1.  public class TestString1 {

2.  public static void main(String[] args){

3.  String str = "420";

4.  str += 42;

5.  System.out.print(str);

6. }

7. }

What is the output?

Given:

11.  StringBuilder sb1 = new StringBuilder("123");

23. String s1 = "123";

24.  // insert code here

25.  System.out.println(sb1 + "" + s1);

Which code fragment,inserted at line 24, outputs"123abc 123abc"?

Given:

1.  public class KungFu {

2.  public static void main(String[] args){

3.  Integer x = 400;

4.  Integer y = x; 5.x++;

6.  StringBuilder sb1 = new StringBuilder("123");

7.  StringBuilder sb2 = sb1;

8.  sb1.append("5");

9.  System.out.println((x==y) + "" + (sb1==sb2));

10. }

11. }

What is the result?

String s1 = new String("info");

s1.concat("soft");

s1.concat("systems");

String s2 = s1.concat("solutions");

Find the total number of objects created?

String s1 = "spring";

String s2 = s1 + "summer";

s1.concat("falls");

s2.concat(s1);

s1+="winter";

System.out.println(s1);

System.out.println(s2);

What is the output?