Find closest number multiple of 10, 100, 1000, 10000,...

ceil-to-nearest.js

/*
  ceilToNearest(5)
  > 10
*/

function ceilToNearest(num) {
	let len = Math.ceil(Math.log10(Math.abs(num) + 1))
	let divisor = Math.pow(10, (len - 1) === 0 ? 1 : (len - 1))
	if (num % divisor > 0) {
		return (Math.round(num / divisor) + 1) * divisor
	}
	return Math.round(num / divisor) * divisor
}