C++ Identifiers

In C++, every variable, function, and object needs a unique name—these are called identifiers. They help programmers reference and manipulate stored values efficiently.

Choosing Identifiers

Identifiers can be short (x, y) or descriptive (engineCapacity, totalMileage). Using clear and meaningful names improves code readability.

Example of Good vs. Vague Naming:

// Good: Clearly describes the stored value
int fuelPerTank = 15;

// Acceptable but unclear: Hard to understand without context
int f = 15;

// Good: Clearly describes the stored value

int fuelPerTank = 15;

​

// Acceptable but unclear: Hard to understand without context

int f = 15;

​

Rules for Naming Identifiers

When creating identifiers, follow these guidelines:

• Allowed: Letters (A-Z, a-z), digits (0-9), and underscores (_).
• Must start with a letter or an underscore (_).
• Case-sensitive: enginePower and EnginePower are different identifiers.
• Cannot contain spaces or special characters (!, #, %, etc.).
• Reserved words (such as int, double, return) cannot be used as identifiers.