Introduction to C Language

Introduction to C Language

• C is a general-purpose high-level programming language.
• Developed by Dennis Ritchie at Bell Labs.
• Created to develop the UNIX operating system.

C History

• Phase 1: Qualitative
• Phase 2: Quantitative
• Phase 3: Design Based

Reasons for C's Popularity

• Easy to learn.
• Structured language.
• Efficient programs.
• Can handle low-level activities (like interacting with hardware).
• Compilable across various platforms.

C vs. C++

• C++ is an extension of C.
• Both have similar syntax.
• C supports classes and objects, while C does not.

Key Program Components

• #include <stdio.h>:
  • Includes the standard input/output library.
  • Allows the program to use functions like printf and scanf.
• int main():
  • The main function: the program's starting point.
  • The int indicates the function returns an integer value (typically 0 for successful completion).
• {}:
  • Encloses the body of the main function.
  • Contains the program's instructions.
• printf("Hello World");:
  • Prints "Hello World!" to the console.
  • printf is a function that displays output.
• return 0;
  • Signals the program's successful completion.
  • The return statement returns a value to the operating system.

Variables and Data Types

• Variables: Storage locations for data.
  • int: Integers (whole numbers).
  • float: Floating-point numbers (numbers with decimals).
  • char: Single characters.
  • double: Double-precision floating-point numbers (for greater precision).

Input and Output

• Input Function:
  • scanf: Reads data from the user (e.g., keyboard).
• Output Function:
  • printf: Displays text or data to the console.

Functions

• Reusable blocks of code that perform specific tasks.

Arrays

• Collections of elements of the same data type.
• Useful for storing and manipulating multiple values together.