What is Pseudocode? – Complete Guide With Examples

If you have just started learning how to code or any Programming, then you must have come across the term Pseudocode.

So, what is Pseudocode? Well, in simple terms, it is a method of describing an algorithm in a programming language using simple everyday wording.

If you read Pseudocode, it looks like a sequence of sentences to do a specific task or solve a problem. Such human-friendly everyday language makes Pseudocode easier to understand for both programmers and non-programmers alike.

As you might be able to tell, Pseudocode is not real code – it is just a representation of code or an algorithm and cannot be executed on a computer like real code. You might also see it mentioned as ‘false code’, ‘representation of code’ or simple instructions to write an algorithm.

So, why use Pseudocode if it’s not real code? Well, writing Pseudocode can help you to understand and plan your code or algorithm better. Also, it is a good way to communicate your ideas with other programmers or with your team.

That’s a very basic overview of Pseudocode but it is probably enough to know if you’re just getting started.

However, if you are interested in further exploring the topic, let’s look into why Pseudocode is used in detail, its benefit in programming and some of the examples to help you fully grasp the concept.

Why use Pseudocode?

As I mentioned earlier, Pseudocode is a way of representing algorithms in a more human-readable format.

As such, it is not a programming language, but rather a way of representing code in a more understandable format. It is written in the same way irrespective of the languages that you’re learning.

Programmers, software developers, or other stakeholders often use Pseudocode as a way to plan out code before actually writing it in a specific programming language.

Most of the time, it’s also written as a way to document code or explain what has already been written in plain language making it easier for everyone involved to easily understand the process or the way code could solve the problem.

Essentially, Pseudocode should offer a high-level description of your algorithm and include details catered to your audience.

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How to Write Pseudocode?

As Pseudocode is meant to be read by humans and not written to be executed by a computer, there is no one right way to write a specific solution.

However, there are some conventions that are commonly used in pseudocode. For example, typically each line of pseudocode represents a single line of code in a programming language.

Pseudocode can be written in any language, making it easier for all stakeholders to understand what the code will be trying to achieve. However, it is often helpful to make the pseudocode more readable and easier to understand.

Learning how to write Pseudocode can be really valuable in your programming journey as it can help you easily communicate your algorithms to other people.

If you are just getting started, here are some tips to help you write better pseudocode:

• Start by writing out the basic structure of your code or algorithm. This can be helpful in getting a high-level overview of what you are trying to achieve.
  
• Make sure to use clear and concise language that can be easily understood by everyone involved.
  
• Avoid using specific syntax or notation from a particular programming language as this can make your pseudocode harder to understand for people who are not familiar with that language.
  
• Try to write out the steps of your code or algorithm in a logical order. This can help you to better understand the flow of your code and identify any potential errors.

You should also take the following aspects into consideration while writing pseudocode solutions;

Clarity

Ensure that your algorithms are unambiguous and written in a clear and concise manner. This will prevent unintended outcomes and make them easier to understand for both yourself and other people.

Correctness

Your pseudocode should be correct in terms of the logic that it is trying to represent and present a solution to solve the problem. This also means that your algorithms should produce the correct results if they were to be executed.

Efficiency

You should write pseudocode with the efficiency of code in mind. Your algorithms should be efficient in terms of time and space. This means that they should run in a reasonable amount of time and use a reasonable amount of memory.

Now that we have gone over some tips on how to write pseudocode, let’s take a look at some examples.

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Pseudocode Examples

Let’s take a look at some pseudocode examples to better understand how it is used.

Example 1: Calculating the Area of a Rectangle

This is a simple example of how pseudocode can be used to represent a basic algorithm. In this case, we are trying to calculate the area of a rectangle.

Start by asking the user for the width and height of the rectangle.

Store the width and height values in separate variables.

Calculate the area of the rectangle by multiplying the width and height values.

Print out the result.

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Example 2: Calculating the Average of a List of Numbers

This is a more complex example of how pseudocode can be used. In this pseudocode example, we are trying to calculate the average of a list of numbers.

Start by asking the user for the number of values in the list.

Store the number of values in a variable.

Create a loop that asks the user to input each value in the list.

Store each value in a separate variable.

Calculate the sum of all the values in the list.

Divide the sum by the number of values to get the average.

Print out the result.

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Example 3: Checking if a Number is Prime

This example shows how pseudocode can be used for a more complex algorithm. In this case, we are trying to check if a number is prime.

Start by asking the user for a number.

Store the number in a variable.

Create a loop that starts from 2 and goes up to the number.

For each number in the loop, check if it is divisible by the number we are checking.

If there is no remainder, then the number is not prime and we can stop the loop.

Otherwise, if the loop finishes without finding a number that is divisible, then the number is prime.

Print out the result. 

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Syntax for Pseudocode

While there is no set syntax for pseudocode, there are some common conventions that are often used. These conventions can help to make your pseudocode clear and easy to understand.

Some common pseudocode conventions include using common keywords like PRINT, WRITE, READ, ‘IF’, ‘THEN’, ‘ELSE’, ‘FOR’, ‘WHILE’, to indicate the type of logic being used.

You can also use mathematical symbols like ‘+’, ‘-‘, ‘*’, ‘/’ to represent arithmetic operations such as addition, subtraction, multiplication, and division.

Another common convention is to use indentation to show the structure of your code. For example, you might use indentation to show that a certain block of code is only executed if a certain condition is met.

if the number is greater than zero

		ask user for another number

	else if the number is zero

		print sum of numbers

Trying to find common keywords and using them frequently can, however, make writing pseudocode complex.

If we were to write example 3 above with the right keywords and closer to a programming language style, it would look like this;

number <-- 17
prime <-- TRUE

FOR i <-- 2 TO number
 IF number is divisible by i THEN
 prime <-- FALSE

IF prime = TRUE:
 OUTPUT "prime"
ELSE
 OUTPUT "not prime"

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Flowcharts to Implement Pseudocode

One way to implement pseudocode is to use a flowchart – diagrams including shapes and flow lines to show the steps in a process or an algorithm. They are easy to create and understand, even for non-programmers.

Flowcharts can be used to represent pseudo code because they show the sequence of steps, as well as the decisions that need to be made along the way.

You can think of Flowcharts as a graphical representation of pseudocode, as they essentially represent a set of instructions.

Creating Flowcharts includes standard symbols that are used to convey different types of instructions. Some of the common symbols used in a flow chart include ovals, rectangles, diamonds, flow lines, and more showing different types of steps.

Symbol	Symbol Name	Usage and Meaning
	Terminal	Start or Stop in the sequence.
	Flowline	Arrow to show the direction of flow.
	Input/Output	Indicates input or output of data.
	Process	Represents an operation that manipulates data.
	Decision	Conditional operation, Yes or No with subsequent paths.

A flowchart is thus a type of diagram that represents an algorithm, workflow or process, made up of boxes representing steps, decisions, inputs and outputs.

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Pseudocode vs Actual Code

The key difference between pseudocode and actual code is that pseudocode is written in plain English (or whichever natural language you are most comfortable with) while code is written in a specific programming language that can be read and executed by a computer.

Pseudocode is not meant to be executed by a machine, but it can be used to create real working code. Many programmers find it helpful to first write out the pseudocode for a project before they start writing actual code.

This allows them to better understand the task at hand and plan their approach. It also helps identify potential errors or areas that need further clarification.

Once the pseudocode is complete, it can then be translated into actual code. This process is often referred to as “flowing up” because the programmer starts with a high-level overview of the task (pseudocode) and then details it step-by-step until they arrive at the working code.

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Pseudocode FAQs

Here’re some of the most frequently asked questions about pseudocode to quickly improve your understanding.

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Summary: Start writing Pseudocode the right way

To summarise, Pseudocode is a text-based description of the steps that a computer program will take to complete a task. It is similar to a recipe in that it provides clear instructions on how to achieve the desired outcome.

In this guide, we took a closer look at what pseudocode is and how it can be used with some real examples.

Writing Pseudocode doesn’t have to be a complex process. It can be as simple as planning your projects in plain English (or your preferred natural language) before you start writing the actual code.

Although it might look like an additional task, Pseudocode could make it much easier to identify potential issues or areas that need further clarification in your project. Besides, once you are done with writing pseudocode, it can be relatively easy to translate it into actual working code.

Writing Pseudocode in the best way possible is indeed an invaluable tool for you to learn and master in your coding journey.