Free Oracle 1Z0-808 Exam Questions

How many String objects are there in the HEAP memory, when control is at Line 9?

1. package com.udayan.oca;

2.  

3. public class Test {

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

5.          String s1 = new String("Java"); //Line 3

6.          String s2 = "JaVa"; //Line 4

7.          String s3 = "JaVa"; //Line 5

8.          String s4 = "Java"; //Line 6

9.          String s5 = "Java"; //Line 7

10.  

11.          int i = 1; //Line 9

12.  

13.      }

14. }

Consider below codes of 3 java files:

1. //M.java

2. package com.sampleproject.oca;

3.  

4. public class M {

5.     public void printName() {

6.         System.out.println("M");

7.     }

8. }

1. //N.java

2. package com.sampleproject.oca;

3.  

4. public class N extends M {

5.     public void printName() {

6.         System.out.println("N");

7.     }

8. }

1. //Test.java

2. package com.sampleproject.oca.test;

3.  

4. import com.sampleproject.oca.*;

5.  

6. public class Test {

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

8.         M obj1 = new M();

9.         N obj2 = (N)obj1;

10.         obj2.printName();

11.     }

12. }

What will be the result of compiling and executing Test class?

Given code of Test.java file:

1. package com.sampleproject.oca;

2.  

3. interface Blogger {

4.     default void blog() throws Exception {

5.         System.out.println("GENERIC");

6.     }

7. }

8.  

9. class TravelBlogger implements Blogger {

10.     public void blog() {

11.         System.out.println("TRAVEL");

12.     }

13. }

14.  

15. public class Test {

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

17.         Blogger blogger = new TravelBlogger(); //Line n1

18.         ((TravelBlogger)blogger).blog(); //Line n2

19.     }

20. }

What will be the result of compiling and executing Test class?

What will be the result of compiling and executing Test class?

package com.udayan.oca;

public class Test {

     private static void add(double d1, double d2) {

         System.out.println("double version: " + (d1 + d2));

     }

     private static void add(Double d1, Double d2) {

        System.out.println("Double version: " + (d1 + d2));

     }

     public static void main(String[] args) {

         add(10.0, null);

     }

}

Given the code fragment: