Appearance

Constant ​

Constant is a value that remains unchanged during the execution of a program. Once defined, its value cannot be modified or reassigned throughout the program's execution. Constants are used to hold values that are expected to remain the same throughout the program's lifetime.

Points
  • Once a constant is defined and assigned a value, that value cannot be altered or modified.
  • Constants are used to represent fixed values that are not expected to change during the execution of a program. Examples include mathematical constants (like π or e), fixed configuration parameters, or values used in algorithms that shouldn't be modified.
  • In many programming languages, constants are named using uppercase letters with underscores to separate words, enhancing readability and distinguishing them from variables.

How to write constant ​

In Python

There is no strict concept of constant variables like in some other programming languages. However, it is a convention to use uppercase variable names for constants to indicate that their values should not be changed. While the language does not enforce immutability, using uppercase names for constants is a widely accepted practice among Python developers.

c
#define PI 3.14159
#define MAX_VALUE 100
c++
const double PI = 3.14159;
const int MAX_VALUE = 100;
java
final double PI = 3.14159;
final int MAX_VALUE = 100
python
PI = 3.14159
MAX_VALUE = 100

Naming Convetions ​

Naming convetions refer to a set of rules and guidelines used for naming variables, functions, classes, and other elements within a program's codebase. These conventions aim to create consistency, readability, and maintainability in the code by establishing a standardized way to name different entities.

Pascal Case
  • capitalizes the first letter of each word in the identifier, including the first word, without using any separators.
  • example: int NumberOfStudents
camelCase
  • he first letter of the first word remains lowercase, and subsequent words have their first letter capitalized. No separators are used
  • example: string fruitName
snake_case
  • words are written in lowercase and separated by underscores (_). In Python, it is common practice for developers to use snake_case when declaring variables
  • example: int number_of_students