# Greatest common divisor

JavaScript, Math, Algorithm, Recursion · Dec 29, 2020

Calculates the greatest common divisor between two or more numbers/arrays.

- The inner
`_gcd`

function uses recursion. - Base case is when
`y`

equals`0`

. In this case, return`x`

. - Otherwise, return the GCD of
`y`

and the remainder of the division`x / y`

.

```
const gcd = (...arr) => {
const _gcd = (x, y) => (!y ? x : gcd(y, x % y));
return [...arr].reduce((a, b) => _gcd(a, b));
};
```

```
gcd(8, 36); // 4
gcd(...[12, 8, 32]); // 4
```