JavaScript finding the largest integer in an array of arrays

Question

function largestOfFour(arr) {
    var newArray = [];
    for(var i =0; i <=arr.length-1; i++){
        console.log(arr[i]);
        newArray[i] = Math.max(arr[i]);
           


        

Answer 1

You are passing an array to Math.max and expect it to return the maximum in that array.

However, Math.max returns the maximum among its arguments. So use

var newArray = [];
for(var i =0; i < arr.length; ++i)
  newArray[i] = Math.max.apply(void 0, arr[i]);

In ES6, you can use arrow functions and the spread operator to simplify:

arr.map(a => Math.max(...a));