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While working on my next article on interviewing programmers I made several mentions to the use of Pseudo code. I started detailing out the uses of Pseudo code and ended up creating a separate post dedicated to the subject. Hopefully this guide will be useful in relation to programmer interviewing but also for general reference for when to use Pseudo code in normal development.

For any complicated development task whether it be a single method or a whole project. It is important that every possible effort is taken to reduce complexity. Extra complexity without need can mean more mistakes are made so breaking a single tasks into two simpler tasks generally results in less complex code and less mistakes.

Writing pseudo code and program code separately simplifies the overall task by splitting it into two simpler tasks. While writing the algorithm the developer can focus on solving the problem, not how it is written in a a particular language. Once the pseudo code is written and has been checked; writing the real code becomes much simpler, the programmer is only concerned with converting the pseudo code into the appropriate program code.

Advantages of Pseudo Code

You don’t have to understand a particular programming language to understand Pseudo Code. It is written in semi-structured, somewhat English like manner. Pseudo code is written so that code based on it should be able to be written in any language (language independent). Using the algorithm the program could be written in C++, C, PHP, Ruby, Java or Visual Basic. Pseudo code can also assist in the natural breaking down of a programming problem into a smaller one that is easier to understand.

The Disadvantages of Pseudo Code

The disadvantages of pseudo code may start with its lack of standards. One person’s logic instructions may not seem as logical to the next. Given the unstructured nature of pseudo code, it is few rules and is hard to standardize. One programmer might not see the logic written by someone else.

Another disadvantage over other modeling tools like flowcharts may be pseudo codes inability to show logic flows or the bigger picture. Whereas flowcharts provide an overview of logic and can be understood at a higher level, pseudo code is far more detail oriented and requires more concentration and practice to see the bigger picture.

How to write Pseudo Code

First you may want to make a list of the main tasks that must be accomplished. Then, focus on each of those tasks. As I stated above you should try to break each main task down into very small tasks that can each be explained with a short phrase. In my experience it is a bad idea to go too close to the correlation of one-to-one between pseudo code and real code. The reason being that your pseudo code is there to help plan the structure but not to help resolve the details that fall out of real world programming.

The use of variables within pseudo code should be restricted if possible but when it is necessary you should show the initialization of the variables. Overall, remember that the purpose of pseudocode is to help the programmer efficiently write code. Therefore, you must attempt to add enough detail and analysis to the pseudo code. It can be that the pseudo code is being written by one programmer and the real code by another. In these circumstances it is best to follow a slightly more strict definition of pseudo code (I have supplied links to a few resources at the bottom).

• Pseudo Code Definition
• Pseudo Code Examples
• Psuedo Code Design
• Algorithms & Pseudo-Code
• Pseudo Code definition at Wikipedia