����ý

Programs are designed using common building blocks. These building blocks, known as programming constructs, form the basis for all programs.

There are three basic building blocks to consider:

• sequence
• selection
• iteration

Sequence is the order in which instructions occur and are processed. Selection determines which path a program takes when it is running. Iteration is the repeated execution of a section of code when a program is running.

There are two types of iteration:

• count-controlled iteration
• condition-controlled iteration

All programs use one or more of these constructs. The longer and more complex the program, the more these constructs will be used repeatedly.

This guide uses pseudo-code examples to illustrate the constructs. It is important to realise that while all programming languages include these constructs, there may be slightly different formats.