What is a C programming

💻 What is a C Program?

A C program is a computer program written in the C programming language, which is a general-purpose, powerful, and fast low-level language. It was developed by Dennis Ritchie in 1972 at Bell Labs to create the Unix Operating System. C is the foundation of many modern programming languages such as C++, Java, and Python.

C is a powerful and efficient language — it allows direct control of memory and is ideal for creating high-performance software.

✨ Key Features of the C Language:

• Fast execution
• Efficient memory management
• Modular programming support
• Portable across platforms

🧠 Example of a Simple C Program:

#include <stdio.h>

int main() {
    printf("Hello, World!\\n");
    return 0;
}

This program simply prints “Hello, World!” on the screen.

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🔹 What are C Tokens?

When writing a C program, each statement is made up of small building blocks. These smallest elements are called tokens. Every valid C program is composed of tokens.

There are 6 types of C tokens:

1. Keywords
2. Identifiers
3. Constants
4. Strings
5. Operators
6. Special Symbols

1️⃣ Keywords

These are predefined, reserved words that have a special meaning to the compiler. C has 32 standard keywords.

int, float, if, else, return, while, for, break, continue, switch, case, char, double, const, void ...

2️⃣ Identifiers

Identifiers are the names used to identify variables, functions, arrays, and other user-defined items in a program. They help the compiler recognize and store data or functions created by the programmer.

Examples: marks, sum, display()

✅ Rules for Naming Identifiers:

• An identifier can include letters (A–Z, a–z), digits (0–9), and underscores (_).
• The first character must be a letter or underscore — it cannot start with a digit.
• Identifiers are case-sensitive (Age and age are different).
• No special characters (like @, #, $, %, etc.) are allowed.
• Keywords (like int, while, return) cannot be used as identifiers.
• Identifier names should be meaningful and readable (e.g., totalMarks, studentName).
• There is no limit to the length of an identifier, but only the first 31 characters are generally considered by compilers.

✅ Valid Examples: _count, num1, total_marks
❌ Invalid Examples: 1num, total marks, @value

3️⃣ Constants

Constants are fixed values that do not change during program execution.

Examples: 10, 3.14, 'A'

4️⃣ Strings

A string is a sequence of characters enclosed in double quotes.

Examples: "Hello", "C Language"

5️⃣ Operators

Operators are special symbols used to perform operations like arithmetic or comparison.

Examples: +, -, *, /, ==, >

6️⃣ Special Symbols

Special characters used to define the structure of a C program.

Examples: (), {}, [], ;, ,

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📘 Conclusion:

C programming is one of the most fundamental and powerful languages ever created. Understanding tokens — especially identifiers and their naming rules — is essential for learning how C programs are structured and interpreted by the compiler. Once you master tokens, writing and debugging C programs becomes much easier.

✍️ Written by: Sakthibala | 📅 Today