Pseudocode & Flowcharts (OCR GCSE Computer Science)

• When designing algorithms there are two main tools that can be used to describe them:

  • Pseudocode

  • Flowcharts

Pseudocode

What is pseudocode?

• Pseudocode is a text based tool that uses short English words/statements to describe an algorithm

• Pseudocode is more structured than writing sentences in English, but is very flexible

Example

• A casino would like a program that asks users to enter an age, if they are 18 or over they can enter the site, if not then they are given a suitable message

• The casino would like the algorithm refined so that the user also enter their first name and this is used to greet the user when they access the site

What is OCR exam reference language?

• OCR exam reference language is the officially designed pseudocode that is seen in OCR based exams to describe algorithms

• Pseudocode has no official syntax so to keep exams consistent OCR have developed their own

Examples

Flowcharts

What is a flowchart?

• Flowcharts are a visual tool that uses shapes to represent different functions to describe an algorithm

• Flowcharts show the data that is input and output, the processes that take place and any decisions or repetition

• Lines are used to show the flow of control

Example

Flowchart

• The casino would like the algorithm refined so that the user also enter their first name and this is used to greet the user when they access the site

Flowchart