Pseudocode, Program Code & Written Descriptions

What is Pseudocode?

Pseudocode is a way of representing algorithms using a combination of natural language and simple programming structures. It is not an actual programming language, but rather a method of outlining the steps in solving a problem or writing a program in a format that is easy to understand.

Why use Pseudocode?

Pseudocode allows programmers to plan and design their programs before actually writing the code. It helps in organizing thoughts and logic, and can be useful in communicating ideas with others. Pseudocode is also independent of any programming language, so it can be easily translated into the desired programming language later on.

How is Pseudocode structured?

Pseudocode follows a logical structure, similar to a real programming language, but without worrying about specific syntactic rules. It uses a combination of statements, conditions, loops, and variables to outline the steps of an algorithm.

Example of Pseudocode:

      algorithm calculateArea
        input: length, width
        output: area
        
        area = length * width
        display "The area is: " + area
      end algorithm
    

Pseudocode is a high-level description of a computer program that uses plain English and simple constructs to outline the logic and algorithm of the program. 

Pros:

• Easy to grasp and comprehend
• Does not require knowledge of any specific programming language
• Helps in planning and designing the program's structure

• Not executable on a computer
• May lack precision and syntax rules, leading to ambiguity

Program code refers to the actual implementation of a computer program using specific programming language syntax and rules. It involves writing lines of code that a computer can understand and execute.

Pros:

• Executable and can produce desired results

• Allows precise control and manipulation of computer resources

• Provides a practical understanding of programming concepts

• Requires knowledge of programming languages

• May involve complex syntax and structures

• Difficult to understand for beginners without proper guidance

Flowcharts visually represent the steps and decision-making process of an algorithm or a program. It uses various shapes and arrows to depict the flow of control and the logical structure of the program.

Pros:

• Provides a clear visual representation of program flow

• Helps in understanding complex algorithms and logic

• Easy to modify and document the program

• Does not provide detailed implementation details

• Can become complex for large programs

• May need additional explanations to comprehend every detail

Program code, often referred to simply as "code," is a set of instructions written in a specific programming language to instruct a computer on how to perform a task or solve a problem. 

Program code must be written using the correct syntax, otherwise the computer will not be able to interpret the code and execute the instructions.

Syntax rules are vital in programming, governing how code is structured for computers to understand. Similar to grammar in language, these rules ensure accurate communication between programmers and machines. Proper syntax is crucial for error-free, readable, and functional code, making it a cornerstone of effective programming.

Program code written with incorrect syntax will result in a syntax error.

When program code is executed it needs to be converted into binary machine code in order for the machine process the instructions. Depending on the programming language this is the job of either a translator, compiler or interpreter.

In order to compile the code it goes through a number of steps, which depending on the language might include:

1. Reprocessing
2. Compiling
3. Assembly
4. Linking.

Before creating a new program it is common to write a written description of the purpose of an algorithm. This description outlines the purpose and functionality of the system so that designers and programmers can then move on with the next step of the design process.

On the programming exam you may be given a written description of an algorithm and be tasked with writing program code which satisfies the requirements of the description.

Example

Write a program that asks the user to input the length, width and height of a cuboid.
Your program should then calculate the volume and surface area of the cuboid
and output the results to the user in an appropriate manner.

Written descriptions have become more important recently with the development of Generative AI chatbots, such as ChatGPT. Programmers can now type in written descriptions of an algorithm ( or components of an algorithm) and the AI will produce executable program that matches the intentions of the description.