Tokens

A token is the smallest individual element in a C++ program that has meaning to the compiler.

Example:

int sum = a + b;

Tokens here are:

int | sum | = | a | + | b | ;

Types of Tokens

1. Keywords

Reserved words with predefined meaning.

int, float, if, else, for, while, return, class, namespace

We can’t use these as variable names.

2. Identifiers

Names given by the programmer to variables, functions, classes, etc.

sum, totalMarks, calculateSalary

Rules:
- Must start with a letter or _
- Can contain letters, digits, _
- Cannot be a keyword

3. Literals (Constants)

Fixed values that do not change during program execution.

10        // integer literal
3.14      // floating literal
'A'       // character literal
"Hello"   // string literal
true      // boolean literal

4. Operators

Symbols that perform operations on operands.

+, -, *, /, %, =, ==, <, >, &&, ||

5. Punctuators / Separators (Special Symbols)

Characters used to structure the program.

; , {} () [] ::

Last modified: 08 February 2026