Functions

Core idea

Functions let you group code into reusable pieces. This makes programs easier to read, test, and update.

Function example

#include <iostream>

int add(int first, int second) {
  return first + second;
}

int main() {
  std::cout << add(3, 4) << "\n";
}

Revision points

• A function can take inputs called parameters.
• A function can return a result.
• Good function names explain what the function does.
• Keep beginner functions small and focused.

What to remember

If logic repeats in multiple places, it usually belongs in a function.

Next step

With functions in place, arrays and strings become easier to work with because you can process collections and text more cleanly.