BCA C Language notes download

 

📘 C Language – Study Notes (Download Version)

1. Introduction to C

• C is a general-purpose, procedural programming language
• Developed by Dennis Ritchie (1972)
• Combines low-level + high-level features
• Used in OS, embedded systems, compilers

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2. History of C

• ALGOL → BCPL → B → C
• C gained popularity due to:
  • UNIX development
  • Efficiency and speed
  • Portability

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3. Structure of a C Program

#include <stdio.h>

int main() {
    printf("Hello World");
    return 0;
}

Components:

• #include → Library inclusion
• main() → Entry point
• Statements → Instructions
• return 0 → Ends program

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4. Functions (Building Blocks)

• A function is a block of code performing a task
• Helps in:
  • Modularity
  • Reusability
  • Easy debugging

Example:

int add(int a, int b) {
    return a + b;
}

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5. Character Set

Includes:

• Letters (A–Z, a–z)
• Digits (0–9)
• Special symbols (+, -, *, etc.)
• Whitespaces

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6. C Tokens

Smallest units in a program

Example:

int a = 5;

Tokens: int, a, =, 5, ;

Types:

• Keywords
• Identifiers
• Constants
• Variables
• Operators

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7. Keywords

• Reserved words with fixed meaning
  Examples: int, float, if, else, return

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8. Identifiers

• Names of variables/functions

Rules:

• Start with letter or _
• Cannot be a keyword
• Case-sensitive

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9. Variables

• Named memory locations

Example:

int age = 20;

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10. Constants

• Fixed values

Types:

• Integer: 10
• Float: 3.14
• Character: 'A'
• String: "Hello"

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11. Data Types

Basic:

• int
• float
• char
• double

Derived:

• Arrays
• Pointers
• Structures

Void:

• No value

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12. Comments

Single-line:

// comment

Multi-line:

/* comment */