Java Programming Part 1
Interface is a contract. It define methods with particular signature any class implement that interface must implement those methods.
Abstract: how the method should look like but have not set how it suppose to do its work.
So, contract based programming includes interface, and abstract class.
Abstract class: mixture of fully implemented method and abstract method. abstract classes can’t be instantiated directly, only subclass can be instantiated. abstract method in abstract class harus must be given type of abstract.
Abstract method: method in the interface, it doesn’t have implementation, it just indicate the method signature. any subclass of any abstract class must implement abstract method.
Java project file to learn about abstract:
credit to lynda.com
