make abstract method in java in interface code example

Example 1: abstract classes and interfaces in java

abstract class have no implementation of methods functions inside it. the classes which extending abstract class have to implement it

Example 2: how to create an abstract method in java

abstract class Scratch{
  // cannot be static
    abstract public void hello();
    abstract String randNum();
}

interface Other{
  //all methods in an interface are abstract
    public void bye();
    String randDouble();
}