OOP IN VB 6.0

Visual Basic 6.0 supports object-oriented language elements and has support for objects distributed in libraries. 

Object Oriented Programming is quite simple and provides way to modularize program by creating partition memory area for both data & function than can be used as template for creating copies of such module.

In the world of OOP, you break a problem down into small parts and solve them individually.

OOP is good for large-scale programming - As your code grows large, there are going to be more and more procedures/functions to your program, and your code is going to be so cluttered that one more look at it, you'd scream.

Class

In Visual Basic 6.0, a class is defined in a class module. A single class module is stored in a special type of file that has a .cls file extension.

In Visual Basic 6.0, the class Initialize event handler named Class_Initialize is used to execute code that needs to be executed at the moment that an object is created.

In Visual Basic 6.0, the keyword is used to disassociate an object variable from an actual object. The Set statement is used to assign to an object variable.

Example: a simple car class

properties of the car class:

• speed
• direction
• engineType
• frameType

methods of the car class:

• accelerate()
• decelerate()
• turnLeft()
• turnRight()

how the car might be used

DIM myCar as Car
SET myCar = new Car
myCar.accelerate()
msgBox myCar.speed

Object:

Our previous working definition as something that contains both data and code is still acceptable called object.

Object is instance of class.