Key Features

Key features of procedural programming Procedures Functions Pre-defined functions Local variables Global variables Parameter passing Modularity Programming libraries

In procedural programing we list a set of steps which have to be executed in that order to achieve something e.g. step 1: Get Value1 step 2: Get Value2 step 3: Get Value3 step 4: Sum=Value1+Value2+Value3 step 5: Average=Sum/3 step 6: Display Average Steps are completed in order

Most Popular Procedural programming language is C. We will be using VB.Net Procedural programming is used in event driven applications as well as in Object Oriented Programming (OOP)

procedure : A procedure is a tried and true process or method used to accomplish a particular task

A function and a method is a self-contained block of code

a segment of code you create yourself, and that can be used whenever you want it.

A Function always returns a value Example:

Code you add to a button would be a block of code, and therefore a function or a method

Variables declared within a function or a method are known as local variables The only work within the parameters of the method Cannot be called or used by any other part of the program

Global variables are declared outside of methods, functions and sub-routines Example: Module MyModule Public MyText As String = "Hello World!" End Module You can call "MyText" like this: MsgBox(MyModule.MyText)

In Visual Basic, you can pass an argument to a procedure by value or by reference. Example:

Private Function CalculateAreaFromRadius(ByVal radius as double) As Double Dim dblRadiusSquared as double Dim dblResult as Double dblRadiusSquared = radius * radius dblResult = dblRadiusSquared * Math.PI

Programmers like to break up their code into being much smaller parts

Manages complexity

These are easier to write/read/understand/debug These separate blocks of code are what's called sub-routines/functions/data/etc. They are stored inside of separate code modules. When we launch the program, these modules are then called. Modules are re-usable

The Base Class Library (BCL) is a Common Language Infrastructure (CLI) standard library available to all CLI languages. CLI includes the BCL in order to encapsulate a large number of common functions, such as file reading and writing, graphic rendering, database interaction, and XML document manipulation Makes the programmer's job easier.

Mainly used with classes Can be created yourself Usually added to your program The .NET Framework is a class library

We have discussed: Procedures Functions Pre-defined functions Local variables Global variables Parameter passing Modularity Programming libraries