C - Identifiers

Identifiers are names for variables, functions, types, etc. They must follow C’s lexical rules.

Learning Objectives

• Recognize valid/invalid identifiers.
• Adopt meaningful naming conventions.

Rules

• Use letters, digits, and underscore only: [A-Za-z_][A-Za-z0-9_]*
• Case-sensitive (count vs Count are different).
• Must not be a keyword.

Valid identifiers

int number1; 
int number2;
int result;
int resultNumber;
int result_number;

Prefer descriptive names: total_price over tp.