Super Keyword in Java — Java Technical Interview Questions & Answers

Super Keyword in Java

Super Keyword in Java

  • super talks to the parent from the child. super.method() calls the parent version. super() calls a parent constructor and must be the first statement in the child constructor.
  • Use super when the child overrides but still wants parent behaviour too. If the parent has no no-arg constructor and you skip super(...), you get a compile error.
  • Putting any code before super() in a constructor is illegal. Interview line: super.method for parent method; super() for parent constructor first.
  • Let's take this on the board with one tiny Main class — no extra files. Super Keyword in Java — output: Parent then Child. super.show() runs Parent first; then Child prints its own line. Start from main, go line by line, and stop at each print. That output is the proof for Super Keyword.

Technical Interview Tip: super() must be the first statement in the constructor.

Code Examples for Super Keyword in Java

Example

class Parent {
  void show() { System.out.println("Parent"); }
}
class Child extends Parent {
  @Override
  void show() {
    super.show();
    System.out.println("Child");
  }
}
public class Main {
  public static void main(String[] args) {
    new Child().show();
  }
}

Super Keyword in Java — output: Parent then Child. super.show() runs Parent first; then Child prints its own line.

How to Explain Super Keyword in Java to an Interviewer

What does super.method() do?

Calls the parent version

Where must super() sit in a constructor?

First statement

When do you need super(...)?

Parent has no no-arg constructor