Super keyword java programs for interview for freshers and experienced

• Lets see some interesting java programs on super keyword.
• Basically super keyword used to refer super class methods and variables. So now let us see how super will work in some scenarios. lets practice.
• Try to answer below java programming interview questions for beginners. 
• Java programs asked in technical interview for freshers and experienced.

Program #1: What will be the output of below java program

1. package com.superkeywordinjava;
2.  public Class SuperDemo{ 
3.  
4. int a,b;
5.  
6. }

1. package com.superkeywordinjava;
2. public Class Subdemo extends SuperDemo{ 
3. int a,b;
4. void disply(){
5. 
   
6. super.a=10;
7. super.b=20;
8.  
9. System.out.println(a);
10. System.out.println(b);
11. System.out.println(super.a);
12. System.out.println(super.b);
13.  
14. }
15.  
16. public static void main (String args[]) {
17.  Subdemo obj= new Subdemo();
18.  
19. obj.a=1;
20. obj.b=2;
21.  
22. obj.disply();
23.  
24. 
    
25.  
26. }
27. }

1. 1
2. 2
3. 10
4. 20

Program #2: What will be the output of below java program

1. 1
2. 2
3. 10
4. 20

Program #3: Basic java programs for interview on super keyword

1. package com.superinterviewprograms;
2. public Class SuperDemo{ 
3.  
4. int a,b;
5.  
6. SuperDemo(int x, int y){
7.  a=x;
8. b=y
9. System.out.println("Super class constructor called ");
10. } 
11.  
12.  
13. }

1. package com.superinterviewprograms;
2.  
3. public Class Subdemo extends SuperDemo{ 
4.  
5. int a,b;
6.  
7. SubDemo(int x, int y){
8. super(10,20);
9.  a=x;
10. b=y
11. System.out.println("Sub class constructor called ");
12. }
13.  
14. public static void main (String args[]) {
15.  Subdemo obj= new Subdemo(1,2);
16. 
    
17.  
18. }
19. }

1. Super class constructor called
2. Sub class constructor called

Program #4: Java interview Program on super keyword

• What will happen if our class constructor having super() call but our class not extending any class.

1. package com.superinterviewprograms;
2.  
3. public Class Sample{ 
4.  
5. Sample(){
6. super();
7. System.out.println("Sample class constructor called "); 
8.  
9. }
10.  
11. public static void main (String args[]) {
12.  
13.  Sample obj= new Sample();
14.  
15. }
16. }

1. Sample class constructor called

• if our class not extending any class Yes still we can use super(); call in our class Because in java every class will extend Object class by default this will be added by JVM. 
•  But make sure we are using only super(); default call we can not place parameterized super call because Object class does not have any parameterized constructor.