Return Largest Numbers in Arrays..help out

Tell us what’s happening:
Hello, i’ve spent hours on this challenge and ive passed all tests except the last one, although my test did run perfectly on repl.it printing all largest numbers in each array. Anyone see what i’m missing? thanks.

Your code so far


function largestOfFour(arr) {
  var newArray = [];
  for (var i=0; i < arr.length; i++){
    var largestNum = 0;
    for(var j=0; j < arr.length; j++){
      if(largestNum < arr[i][j]){
         largestNum = arr[i][j];
      }
    }
    newArray.push(largestNum);
  }
  return newArray;
}

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

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Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-algorithm-scripting/return-largest-numbers-in-arrays