Naming Convention in C Programming

C Basic Concepts

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.

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

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

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

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

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

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