const largestOfFour = (arr) => {
  let newArray = [];    /* declare a a varible assign an empty array */
  for (let i = 0; i < arr.length; i++) { /* first loop through the first level array to determine its length*/
    let firstNum = arr[i][0];    /*because we have a Multidimensional Array declare a
                                 variable and capture [0] element of each inner array */
    for (let j = 0; j < arr[i].length; j++) { /*loop through the inner array's length */
      if (arr[i][j] > firstNum) { /* use an if statement to determime if each element of our inner array
                                  is greater than the first element assigned to our firstNum variable */
        firstNum = arr[i][j];  /* if it greater replace the previous element with a new greater number */
      }
    }
    newArray[i] = firstNum; /* assign our new elements to create a newArray of greater numbers */
  }
  return newArray;  /*return a new array with greater values */
}

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