Objects

Objects are often described as follows:

• An object has identity (it acts as a single whole).
• An object has state(it has various properties, which might change).
• An object has behavior (it can do things and can have things done to it).

It is useful (but not quite accurate) to think of an object as a contiguous chunk of memory that contains both data and machine code, as in the picture.

Of course, general purpose memory (symbolized by the yellow bricks in the picture) can hold both data and machine code. So an object can be built out of general purpose memory.

In object oriented programming, a subroutine of an object is often called a method of the object. So an object consists of data and methods.