In C, a function is a reusable block of code that performs a specific task. It helps you organize, reuse, and modularize your program. ??

? Basic Structure of a Function

c
return_type (parameter_list) {    // body of the function}

? Example: A Simple Function

c
#include // Function declarationvoid greet();  int main() {    greet();  // Function call    return 0;}// Function definitionvoid greet() {    printf("Hello from a function!\n");}

? Types of Functions

1. No arguments, no return value

   c
   void sayHello();
   

2. Arguments, no return value

   c
   void greetUser(char name[]);
   

3. No arguments, return value

   c
   ();
   

4. Arguments and return value

   c
   int add(int a, int add(int x, int y) {    return x + y;}int main() {    int result = add(3, 4);    printf("Sum = %d\n", result);    return 0;}
   

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   ? Function Components

   
   

   Part	Description
   Declaration	Tells the compiler the function exists
   Definition	Actual code block of the function
   Call	Where the function is used

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   ? Why Use Functions?

   • Avoid code repetition

   • Make programs easier to read & maintain

   • Break down complex problems into smaller tasks