FreeCodeCamp:Chunky Monkey

要求：

猴子吃香蕉可是掰成好几段来吃哦！

把一个数组arr按照指定的数组大小size分割成若干个数组块。

例如:chunk([1,2,3,4],2)=[[1,2],[3,4]];

chunk([1,2,3,4,5],2)=[[1,2],[3,4],[5]];

结果：

chunk(["a", "b", "c", "d"], 2) 应该返回 [["a", "b"], ["c", "d"]].
chunk([0, 1, 2, 3, 4, 5], 3) 应该返回 [[0, 1, 2], [3, 4, 5]].
chunk([0, 1, 2, 3, 4, 5], 2) 应该返回 [[0, 1], [2, 3], [4, 5]].
chunk([0, 1, 2, 3, 4, 5], 4) 应该返回 [[0, 1, 2, 3], [4, 5]].
chunk([0, 1, 2, 3, 4, 5, 6], 3) 应该返回 [[0, 1, 2], [3, 4, 5], [6]].
chunk([0, 1, 2, 3, 4, 5, 6, 7, 8], 4) 应该返回 [[0, 1, 2, 3], [4, 5, 6, 7], [8]].

代码：

方法1：

function chunk(arr, size) {
  // Break it up
  var temp = [];
  var result = [];

  for (var a = 0; a < arr.length; a++) {
    if (a % size !== size - 1)
      temp.push(arr[a]);
    else {
      temp.push(arr[a]);
      result.push(temp);
      temp = [];
    }
  }

  if (temp.length !== 0)
    result.push(temp);
  return result;
}

方法二：

function chunk(arr, size) {
  // Break it up
  // It's already broken :(
  arr = arr.slice();
  var arr2 = [];
  for(var i = 0, len = arr.length; i < len; i+=size) {
    arr2.push(arr.slice(0, size));
    arr = arr.slice(size);
  }
  return arr2;
}

方法三：

function chunk(arr, size) {
  // Break it up.
  var newArr = [];
  var i = 0;

  while (i < arr.length) {
    newArr.push(arr.slice(i, i+size));
    i += size;
  }
  return newArr;
}
chunk(["a", "b", "c", "d"], 2);

方法四：

function chunk(arr, size) {
  // Break it up
  var newarr=[];
  
  for (var i=0;i<arr.length;i+=size){
    newarr.push(arr.slice(i,i+size));
  }
  return newarr;
}

chunk(["a", "b", "c", "d"], 2);