如何重复数组元素以形成n×m维数组或矩阵

function repeatArrayElements(arr, n, m) {
  var newArr = [];
  for (var i = 0; i < n; i++) {
    for (var j = 0; j < m; j++) {
      newArr.push(arr[i % arr.length]);
    }
  }
  return newArr;
}

var originalArray = [1, 2, 3];
var repeatedArray = repeatArrayElements(originalArray, 3, 4);
console.log(repeatedArray);

function repeatArrayElements(arr, n, m) {
  var newArr = [];
  for (var i = 0; i < n; i++) {
    newArr = newArr.concat(arr);
  }
  return newArr;
}

var originalArray = [1, 2, 3];
var repeatedArray = repeatArrayElements(originalArray, 3, 4);
console.log(repeatedArray);