factorial

factorial(n): bigint

Defined in: factorial.ts:26

The factorial n! = 1 × 2 × … × n, with 0! = 1.

Returns a bigint because 21! already exceeds Number.MAX_SAFE_INTEGER.

Amortised O(1) for repeated calls at or below 256, which is where the consumers sit: the table is extended only as far as it has not already reached. Above that the tail is multiplied out each time rather than stored.

Parameters

n

number

A non-negative integer.

Returns

bigint

n! as an exact integer.