An interface is a special kind of class that cannot be instantiated.
The main idea of an interface is declaring functionality. Interfaces help to
abstract from specific classes and emphasize the functionality.
It makes software design more reusable and clean
Opposite to a class, an interface can extend several interfaces.
A class can implement multiple interfaces.Public abstract interface Multi{ //Interface declaration
Public abstract void multi();//method declaration
public abstract void subtract();
}In many cases, it is more important to know what an object can do,instead of
how it does what it does. This is a reason why interfaces are commonly used for
declaring a type of variable.
interface : DrawingTool : a tool can draw
interface DrawingTool {
void draw(Curve curve);
}
DrawingTool pencil = new Pencil();
DrawingTool brush = new Brush();
Both Pencil and brush class should implement draw method/* File name : Animal.java */
interface Animal {
public void eat();
public void travel();
}