Recursion

A function calling itself to solve a smaller piece of the same problem.

What is Recursion in JavaScript?

Recursion — A function calling itself to solve a smaller piece of the same problem.

function countdown(number) {
    if (number === 0) {
        return 0;
    }

    return 1 + countdown(number - 1);
}

Level: Journeyman · More JavaScript terms at this level

Updated September 27, 2026