In arrays FreeCodeCamp

Return an array consisting of the largest number from each provided sub-array. For Simplicity, the provided array will contain exactly 4 sub-arrays. Remember, you can iterate through an array with a simple for loop, and access each member with array syntax arr[i] [should return an array] --:: Tiempo estimado más de 60 minutos ::--

by Joel Garcia

JavaScript

/* 

Return an array consisting of the largest number
from each provided sub-array.

For Simplicity, the provided array will contain
exactly 4 sub-arrays.

Remember, you can iterate through an array
with a simple for loop, and access each member
with array syntax arr[i] [should return an array]

--:: Tiempo estimado más de 60 minutos ::--

*/

function largerstOfFour(arr) {
		return arr.map(function(group) {
      return group.reduce(function(prev, current) {
        return current > prev ? current : prev;
      });
    });
}

console.log(
	largerstOfFour(
      [
          [17,23,25,12],
          [25,7,34,48],
          [4,-10,18,21],
          [-72,-3,-17,-10]
      ]
  )
)

function largestOfFour(arr) { 
	var res = []; 
   for (var n = 0; n < arr.length; n++) { 
  	var larger = arr[n][0];
    for (var i = 1; i < arr[n].length; i++) {
    	if (arr[n][i] > larger) {
      	larger = arr[n][i]; 
      } 
     } 
     res[n] = larger; 
  } 
  return res; 
 }