Pseudocode Overview and Constructs

Pseudocode

Overview

Pseudocode is a technique used to describe the distinct steps of an algorithm in a manner that's easy to understand. By using pseudocode, developers can focus their attention on the thought process behind the algorithm, which helps in designing and validating algorithms without being limited by a specific programming language's syntax rules. This approach allows for quick bug detection as pseudocode is written in a human-readable format, making it easier to edit and discover bugs before writing actual code.

Main Constructs of Pseudocode

The main constructs of pseudocode include the following keywords, often referred to as "keywords":

• SEQUENCE represents linear tasks sequentially performed one after another.
• WHILE is a loop with a condition at its beginning.
• REPEAT-UNTIL is a loop with a condition at the bottom.
• FOR is another way of looping.
• IF-THEN-ELSE is a conditional statement changing the flow of the algorithm.
• CASE is the generalization form of IF-THEN-ELSE.

These constructs describe the control flow of the algorithm. Additionally, invoking classes or calling functions uses the CALL keyword, while handling exceptions uses the EXCEPTION, WHEN keywords.

Writing Pseudocode

When writing pseudocode, follow these guidelines:

1. Make only one statement per line.
2. Capitalize the initial word of a line.
3. Use indentations to show hierarchy and nested constructs.
4. Use the naming domain of the problem, not of the implementation.
5. Keep statements simple, readable, and programming language independent.

Pseudocode can act as a rough draft for coding projects and may even be included as docstrings at the beginning of the code file.

Variables

Variables can store all five different types of data in pseudocode: Boolean, Integer, Character, String, Float/Decimal/Real. They allow easy access to stored values for use in conditional statements, loops, or mathematical operations. Variables can be declared and assigned values, and constants Declaration, assignment, and usage follow similar rules in pseudocode.

Functions

Functions in pseudocode serve the purpose of structuring programs, avoiding long codes, and making code easier to modify. They are defined and then called when needed during program execution. Functions perform specific tasks or calculations.

Loops

Loops in pseudocode are sequences of cyclic instructions that allow us to repeat an action until a condition is met. There are mainly three types of loops: DO, WHILE, and FOR. These loops save time and lines of code by allowing structured repetition in algorithms.

Algorithms

Algorithms are problem-solving procedures consisting of a well-defined, ordered, and finite sequence of instructions, executed in a logical manner. To execute all steps in the desired sequence, there are different control structures like conditionals or loops available.

Conditions

Conditions in pseudocode determine the path execution takes based on certain criteria. There are three main types of conditions: simple, alternative, and chained. Conditions help in choosing between performing one action or another, depending on whether a certain condition occurs.