Find the largest number of each array inside another array

largestItemsOfManyArrays.js

function largestOfManyArrays(arr) {
  function largestItemOfAnArray(arr) {
    return arr.sort(function (a, b) { return b - a; }).shift();
  }
  
  var largestOfEachArray = arr.map(function(array) {
    return largestItemOfAnArray(array);
  });
  return largestOfEachArray;
}

largestOfManyArrays([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);

I'm going to choose better names for the functions and the for the gist 😂