maxMinValueIndex.js

// how to get the index of the max/min element in an array

let scores = [2, 0, -1, 7, 1];

console.clear();

let scoreIndex = scores.reduce(
	(iMax, x, i, arr) => x > arr[iMax] ? i : iMax, 0);

console.log('calc max index', scoreIndex);

scoreIndex = scores.reduce(
	(iMin, x, i, arr) => x < arr[iMin] ? i : iMin, 0);			

console.log('calc min index', scoreIndex);