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Understanding Identifiers in C++

Identifiers are names given to variables, functions, classes, etc., to identify them uniquely in the code. They must follow certain rules in C++.

Key Topics

Rules for Identifiers

  • Must begin with a letter (a-z, A-Z) or underscore (_)
  • Can contain letters, digits (0-9), and underscores
  • Case-sensitive (Rudra and rudra are different)
  • Cannot be a reserved keyword (e.g., int, class)

Examples of Valid and Invalid Identifiers

Valid Identifiers

int Tamilmaran;
float salary_2023;
char _initial;

Invalid Identifiers

int 2ndPlace;   // Starts with a digit
float double;     // 'double' is a reserved keyword
char first-name;  // Hyphen is not allowed

Code Explanation: Valid identifiers follow the naming rules, while invalid ones violate them by starting with digits, using reserved keywords, or containing illegal characters.

Key Takeaways:

  • Choose meaningful identifiers to enhance code readability.
  • Adhere to naming conventions and rules.
  • Avoid using reserved keywords as identifiers.
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