Naming Convention in C Programming

C Basic Concepts

In this lesson, we will learn about the Naming Convention in the C programming language. We will go through the rules of naming, along with examples and a quiz on it.

What is Naming Conventions

In C programming, naming conventions are set of rules for choosing the valid name to be used for variables in a C program.

Naming Conventions rules for Variables are:

It should begin with an alphabet.
There may be more than one alphabet, but without any spaces between them.
Digits may be used but only after alphabet.
No special symbol can be used except the underscore (_) symbol. When multiple words are needed, an underscore should separate them.
No keywords or command can be used as a variable name.
All statements in C language are case sensitive. Thus a variable A (in uppercase) is considered different from a variable declared a (in lowercase).

Now let's see some examples for more understanding.

Example 1

It should begin with an alphabet.

x     // x is a valid variable name because it starts with an alphabet x

Example 2

There may be more than one alphabet, but without any spaces between them.

total    // total is a valid variable name as there is no space between alphabets

Example 3

Digits may be used but only after alphabet.

ar15    // ar15 is a valid variable name as digits have been used after the alphabet
a6b2    // a6b2 is a valid variable name as digits have been used after the alphabet

Example 4

No special symbol should be present within the variable name except underscore _.

total_cost     // total_cost is a valid variable name as there is an underscore
total cost     // total cost is an invalid variable name as there is a space
total-cost     // total-cost is an invalid variable name as there is a hyphen
total$         // total$ is an invalid variable name as there is a dollar symbol

Example 5

No keywords or command can be used as a variable name.

for     // here for is an invalid variable name because it is a keyword in C
if      // if is an invalid variable name because it is a keyword in C
case    // case is an invalid variable name because it is a keyword in C
const   // const is an invalid variable name because it is a keyword in C

Example 6

All statements in C language are case sensitive. Thus a variable A (in uppercase) is considered different from a variable declared a (in lowercase).

a     // a is a valid variable written in lowercase
A     // A is a valid variable written in uppercase so both are different variables

Test Your Knowledge

Attempt the multiple choice quiz to check if the lesson is adequately clear to you.

MCQ Quiz

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