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Most programs are developed using programming languages. These languages have specific syntax that must be used so that the program will run properly.

Pseudo-code is not a programming language. Instead, it is a simple way of describing a set of programming instructions in a manner that resembles a programming language. Pseudo-code has its own syntax, some of which is very similar to many actual programming languages. Any algorithms designed using pseudo-code will not run unless they are converted into an actual programming language.

This simple pseudo-code algorithm asks a user to input what their favourite subject is:

WHILE answer <> 'computer science' DO
                         SEND 'What is your favourite subject?' TO 
                         DISPLAY
                         RECEIVE answer FROM (STRING) KEYBOARD
                         IF answer = 'computer science' THEN
                              SEND 'Good choice!' TO DISPLAY
                         ELSE
                              SEND 'Really? ' TO DISPLAY
                         END IF
                    END WHILE

Advantages and disadvantages of pseudo-code

Designing an algorithm in pseudo-code has advantages because:

• it can be quickly and easily converted into an actual programming language as it is similar to a programming language
• it is fairly easy to understand, even for non-programmers
• it does not matter if there are errors in the syntax - it is usually still obvious what is intended
• changes to the design can be incorporated quite easily

Pseudo-code also has its disadvantages:

• It can be hard to see how a program flows. For example, where does following one path as opposed to another take the program?
• It can be time consuming to produce.

Pseudo-code covers many areas of programming and there are different variants. The specific pseudo-code syntax for the Edexcel GCSE Computer Science course can be found at the end of the .