30-seconds-of-code/snippets/sortedIndex.md

sortedIndex

Returns the lowest index at which value should be inserted into array in order to maintain its sort order

const sortedIndex = (arr,n) => {
    arr[0] > arr[1] ? (anarray = arr.reverse(),isReversed = true) : (anarray = arr,isReversed = false);  
	val = anarray.findIndex( el => {
	return n <= el
    })
	return val === -1 ? arr.length : isReversed ? arr.length - val : val
}

sortedIndex([5,3,2,1], 4); // 1
sortedIndex([30,50],40); // 1