What is Pseudocode?

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In computer science, we often come across terms like flowcharts and algorithms. Most of us are familiar with these two terms. Do you know what is pseudocode? Is it the same as a flowchart or algorithm? Or is it an entirely different term? Let’s understand what is pseudocode.

What is Pseudocode?

Pseudocode is an informal way of programming description that does not require any strict programming language syntax or underlying technology considerations. It is used for creating an outline or a rough draft of a program. Pseudocode summarizes a program’s flow but excludes underlying details. System designers write pseudocode to ensure that programmers understand a software project’s requirements and align code accordingly.

Pseudocode is not an actual programming language. So it cannot be compiled into an executable program. It uses short terms or simple English language syntaxes to write code for programs before it is actually converted into a specific programming language.

This is done to identify top-level flow errors and understand the programming data flows that the final program is going to use. This definitely helps save time during actual programming as conceptual errors have been already corrected.

Firstly, program description and functionality are gathered, and then pseudocode is used to create statements to achieve the required results for a program. Detailed pseudocode is inspected and verified by the designer’s team or programmers to match design specifications. Catching errors or wrong program flow at the pseudocode stage is beneficial for development as it is less costly than catching them later.

Once the pseudocode is accepted by the team, it is rewritten using the vocabulary and syntax of a programming language. The purpose of using pseudocode is an efficient key principle of an algorithm. It is used in planning an algorithm by sketching out the structure of the program before the actual coding takes place.

Pseudocode vs Algorithm

Algorithm

It’s an organized logical sequence of the actions or the approach towards a particular problem. A programmer implements an algorithm to solve a problem. Algorithms are expressed using natural verbal but somewhat technical annotations.

Pseudocode

It’s simply an implementation of an algorithm in the form of annotations and informative text written in plain English. It has no syntax like any of the programming languages and thus can’t be compiled or interpreted by the computer.

Let’s look at the following example of linear search to understand the difference between the two.

Algorithm of Linear Search

1. Start from the leftmost element of arr[] and 
one by one compare x with each element of arr[]. 
2. If x matches with an element, return the index. 
3. If x doesn’t match with any of elements, return -1.

Pseudocode of Linear Search

FUNCTION linearSearch(list, searchTerm):
     FOR index FROM 0 -> length(list):
       IF list[index] == searchTerm THEN
           RETURN index
       ENDIF
       ENDLOOP
           RETURN -1
END FUNCTION 

From the above example, we notice the following about algorithm and pseudocode:

1. An algorithm is defined as a well-defined sequence of steps that provides a solution for a given problem, whereas pseudocode is one of the methods that can be used to represent an algorithm.
2. While algorithms are generally written in a natural language or plain English language, pseudocode is written in a format that is similar to the structure of a high-level programming language.

Advantages of a Pseudocode

• Improves the readability of any approach. It’s one of the best approaches to start the implementation of an algorithm.
• Acts as a bridge between the program and the algorithm or flowchart. Also works as rough documentation, so the program of one developer can be understood easily when a pseudo code is written out. In industries, the approach of documentation is essential. And that’s where a pseudo-code proves vital.
• The main goal of pseudocode is to explain what exactly each line of a program should do, hence making the code construction phase easier for the programmer. 

Disadvantages of a Pseudocode

• Pseudocode does not provide a visual representation of the logic of programming.
• There is no proper format for writing the pseudocode.
• In pseudocode, there is an extra need to maintain documentation.
• In pseudocode, there is no proper standard different companies follow their own standard for writing the pseudocode.

How to Write Pseudocode

1. Arrange the sequence of tasks and write the pseudocode accordingly.
2. Start with the statement of pseudocode which establishes the main goal or the aim.
Example:

This program will allow the user to check
the number whether it's even or odd.

3. The way the if-else, for, while loops are indented in a program, indent the statements likewise, as it helps to comprehend the decision control and execution mechanism. They also improve the readability to a great extent.
Example:

if "1"
      print response
          "I am case 1"
if "2"
      print response
          "I am case 2"

4. Use appropriate naming conventions. The human tendency follows the approach to follow what we see. If a programmer goes through a pseudo code, his approach will be the same as per it, so the naming must be simple and distinct.
5. Use appropriate sentence casings, such as CamelCase for methods, upper case for constants, and lower case for variables.
6. Elaborate everything which is going to happen in the actual code. Don’t make the pseudo code abstract.
7. Use standard programming structures such as ‘if-then’, ‘for’, ‘while’, ‘cases’ the way we use it in programming.
8. Check whether all the sections of pseudocode are complete, finite, and clear to understand and comprehend.
9. Don’t write the pseudo code in a complete programmatic manner. It is necessary to be simple to understand even for a layman or client, hence don’t incorporate too many technical terms.