Introduction to C

C is a powerful, general-purpose programming language that's been influential in modern computing—forming the foundation of many operating systems, embedded systems, and performance-critical applications.

Example 1: Hello World

#include int main() { printf("Hello, World!\\n"); return 0; }
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Explanation: This basic program uses printf from stdio.h to display a message. Every C program starts with main().

Example 2: Addition

#include int main() { int a = 5, b = 3; printf("Sum = %d\\n", a + b); return 0; }
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Explanation: Declares two integers, adds them, and prints the result using %d format specifier.

Example 3: Loop

#include int main() { for(int i = 1; i <= 5; i++) { printf("%d ", i); } printf("\\n"); return 0; }
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Explanation: A for loop prints numbers from 1 to 5, showcasing iteration in C.

Example 4: Function

#include int multiply(int x, int y) { return x * y; } int main() { int res = multiply(4, 5); printf("Product = %d\\n", res); return 0; }
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Explanation: Defines a function multiply, calls it in main(), and prints the returned result.

🧠 C Quiz

  1. Which header file is needed for printf?
  2. How do you start the main function?
  3. What symbol is used to include a header file?