What happens, if two interfaces contain the same default method?

Question

If I have two interface with the same default method and both are implementing with a class/ See this program.

interface alpha {
  default void reset() {
    System.out.println("This is alpha version of default");
  }
}

interface beta {
  default void reset() {
    System.out.println("This is beta version of default");
  }
}

class MyClass implements alpha, beta {
  void display() {
    System.out.println("This is not default");
  }
}

class main_class {
  public static void main(String args[]) {
    MyClass ob = new MyClass();
    ob.reset();
    ob.display();
  }  
}

then what will happen? And also I am getting unrelated error with this program.

Answer 1

You cannot implement multiple interfaces having same signature of Java 8 default methods (without overriding explicitly in child class)

. You can solve it by implementing the method E.g.

class MyClass implements alpha, beta {
  void display() {
    System.out.println("This is not default");
  }

  @Override
  public void reset() {
    //in order to call alpha's reset
    alpha.super.reset();
    //if you want to call beta's reset 
    beta.super.reset();

  }
}