What is Pseudo Code?

Most programs on your computer have been written using a programming language of some sort, for example in C#, Python, Java, Visual Basic…

Before a programmer jumps in and begins coding a program, they usually need to plan how this program is going to work. To do this, they will use pseudo code to write out a ‘plan’ of their program – usually in the form of an algorithm.

Now, pseudo code is not technically a programming language, but it does use certain command words to help a user know how the program is running; here are a few keywords that BBC Bitesize recommend you might use in your pseudo code…

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Let’s have a look at writing a simple program in pseudo code.

Write a program that will ask a user to enter two numbers, add them together and display the outcome.

First of all, we need to ask a user to enter two numbers…

INPUT firstNumber
INPUT secondNumber

Once we have entered our two numbers, we need to add them together

total = firstNumber + secondNumber

And finally, we need to output the result…

OUTPUT total

So altogether, our pseudo code would look like…

INPUT firstNumber
INPUT secondNumber
total = firstNumber + secondNumber
OUTPUT total

Some exam questions may be a bit trickier to answer than this, however if you remember all computer systems follow the basic structure

INPUT – PROCESS – OUTPUT

So each algorithm should have:

  • Something going in, whether that is an input or variable
  • A process of some kind, possibly arithmetic or logic
  • Something coming out, whether that is displayed to the user or stored in a variable

Have a go at some of the OCR algorithm challenges and see how you get on, it’s a good idea to practice these often because it takes some time to master!