C Tokens

In C programming, the smallest individual units of a program are known as tokens. Tokens are the basic building blocks of a C program.

Types of C Tokens

C tokens are classified into six types:

• Keywords
• Identifiers
• Constants
• Strings
• Operators
• Special Symbols

1. Keywords

Keywords are reserved words in C that have special meanings. They cannot be used as variable names. Examples of keywords include:

int, float, char, return, if, else, while, for, switch, break

2. Identifiers

Identifiers are the names used for variables, functions, arrays, etc. They must begin with a letter or an underscore (_) and can be followed by letters, digits, or underscores.

3. Constants

Constants are fixed values that do not change during program execution. They can be:

• Integer Constants: e.g., 10, -50, 1000
• Floating-point Constants: e.g., 3.14, -0.001, 2.5e3
• Character Constants: e.g., 'A', '5', '*'

4. Strings

Strings in C are sequences of characters enclosed in double quotes (" "). Example:

"Hello, World!", "C programming"

5. Operators

Operators are symbols that perform operations on variables and values. Some examples include:

• Arithmetic Operators: +, -, *, /, %
• Relational Operators: ==, !=, >, <,>=, <=
• Logical Operators: && (AND), || (OR), ! (NOT)

6. Special Symbols

These include symbols such as brackets, commas, semicolons, etc., used for syntax structuring. Example:

• ; (Semicolon - statement terminator)
• { } (Curly braces - block of code)
• ( ) (Parentheses - function parameters)

Example Program

Below is a simple program demonstrating the use of various tokens:

#include <stdio.h>

int main() {
    int num = 10; // Identifier and integer constant
    float pi = 3.14; // Floating-point constant
    char letter = 'A'; // Character constant

    printf("Number: %d\n", num);
    printf("Pi: %.2f\n", pi);
    printf("Letter: %c\n", letter);

    return 0;
}

Explanation

• int, float, char - Keywords.
• num, pi, letter - Identifiers.
• 10, 3.14, 'A' - Constants.
• printf() - Function for displaying output.

If you have any questions, feel free to ask. Thank you for reading!