Mutating combination function (zero changes to array length)

mutate.ts

function combine(strings: string[], length: number): string[] {
	// Init results array of required length, filled with empty strings
	const combinations = Array(strings.length**length).fill('')
	for (let i = length; i > 0; i--) {
		  for (let j = 0; j < combinations.length; j++) {
		      combinations[j] += strings[Math.floor(j/(strings.length**(i-1)))%strings.length]
		  }
	}
	
	return combinations
}

const combined = combine(["a", "b", "c"], 3)
console.log(combined)