Why do we use interfaces in java?

[jessie143143]

Interfaces define only declaration of methods and final data members.We use them when we want different definitions of methods in different classes for different purposes.
To implement multiple inheritance in Java we must use interfaces in which one class can implement one or more than one interfaces.

[venkatjaya]

Using interfaces allows you to substitute multiple implementations that conform to the interface (think plugins) while using a specific class hard-codes you to the class or its descendants. Interfaces also allow you to mimic multiple inheritance since classes can implement more than one interface but can only extend a single base class.







.........................................................................................................