An interface describes what functions an implemented class will have to code. E.g. if a class was a car and the interface had functions for how many doors etc, then a class of Vauxhall that implements the interface would have to code the function to return the correct amount of doors.
Here is the code, I usually find the code explains it better.
// defines the fuctions that have to be implemented by a implementable class interface implementThese { void printHi(); // have to implement these void printBye(); } // the interClass will implement the interface implementThese class interClass implements implementThese { public void printHi() { System.out.println("Hi"); } public void printBye() { System.out.println("Bye"); } } class inter { public static void main(String args[]) { interClass in = new interClass(); // call the classes functions. in.printHi(); in.printBye(); } } |
If you save as inter.java, and then run the output will be
Hi Bye
There can be many interfaces per class to be implemented.