Lesson 10 / 36

Function Basics

Package reusable logic into named blocks.

Why functions?

A function is a named block of code you can call repeatedly instead of copy-pasting. It takes inputs (parameters), does work, and can send back a result (return value).

Anatomy of a function

Every function has a return type, a name, a parameter list, and a body.

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

int main(void) {
    int result = add(3, 4);
    printf("%d\n", result);
    return 0;
}

Output:

void means nothing

A function that returns nothing uses void as its return type. void greet(void) { printf("Hi\n"); }