Java :IS-A and HAS-A

IS-A and HAS-A

http://stackoverflow.com/questions/9677545/what-do-has-a-and-is-a-mean?lq=1
http://stackoverflow.com/questions/2218937/has-a-is-a-terminology-in-object-oriented-language

Has-a means that the Class in question 'has a' field of a type.

Is-a means that the Class extends from a superclass or implements an interface. The instanceof operator would return true if tested against a class in the this case.

Example

class SteeringWheel{}

class Vehicle{}

interface transport 

class Car extends Vehicle implements transport
{
    SteeringWheel  sWheel;
   
}

• A car is-a vehicle and it is for transport
• A car has-a steering wheel