2.1.3 Thinking Procedurally

Why does thinking procedurally make writing a program easier

breaks down problem into smaller parts which are easier to understand and easier to design

First stage of thinking proceduraly

Problem decomposition - large, complex problem is continually broken down into smaller subproblems. Problem becomes more feasible to manage and can be divided between a group of people according to the skill stes of individuals,

How are problems decomposed

top-down design. Breaks down problems into levels. Higher levels provide an overview of a problem while lower levels specify in detail the components of this problem

Aim of top-down design

to keep splitting problems into sub-problems until each sub-problem can be represented as a single task and a self-contained module or subroutine. Each task can then be solved and developed as a subroutine by a different person. Each subroutine can be tested separately before being integrated

Second stage of thinking procedurally

Identify the components of the solution and assess how its best to be solved. Useful to identify tasks which can be solved using an already existing module, subroutine or library. The components are combined to form a full, working solution.

What to consider when combining components to form a full solution

The order in which operations are performed is important. Some subroutines might require data from other subroutines or the user before they are able to execute, so will be unable to execute simultaneously.