Introduction

C is a general-purpose programming language originally developed at Bell Labs in the 1970s. It was designed by Dennis Ritchie for system programming, but it's widely used in various application domains.

Applications

• Operating Systems: Many operating systems are written in C or have components written in C (e.g., Unix, Linux).
• Embedded Systems: C is prevalent in embedded systems like microcontrollers and IoT devices.
• Game Development: It's used for game development, especially in writing game engines.
• Compiler Development: C is often used to develop compilers and interpreters for other languages.

Example: Hello World program in C

  #include

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

Popularity

C has a strong legacy and is still widely used in industry and education due to its powerful features and low-level capabilities.

Getting Started with C

Constants, Variables, and Keywords

Constants:

Constants in C are values that do not change during program execution. They can be of different types, including integer constants (e.g., 42), floating-point constants (e.g., 3.14), and character constants (e.g., 'A').

Variables:

Variables are used to store data that can change during program execution. You must declare variables with a data type before using them.

Data Types:

C supports various data types, including:

• int: For integers.
• float: For floating-point numbers.
• char: For characters.
• double: For double-precision floating-point numbers.

Keywords:

Keywords are reserved words in C and cannot be used as identifiers (variable or function names). Examples include "int," "if," "while," "return," and "break."

Example:

#include 

int main() {
    int age;  // Declaration of an integer variable
    age = 30; // Assignment of a value to the variable
     printf("My age is %d years.\n", age);
  return 0;
}
        

Note: C is case-sensitive, so "Age" and "age" would be treated as different variables.