FreeCodeCamp:Chunky Monkey

Posted 2020-08-19 tmj

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：

 1 function chunk(arr, size) {
 2   // Break it up
 3   var temp = [];
 4   var result = [];
 5 
 6   for (var a = 0; a < arr.length; a++) {
 7     if (a % size !== size - 1)
 8       temp.push(arr[a]);
 9     else {
10       temp.push(arr[a]);
11       result.push(temp);
12       temp = [];
13     }
14   }
15 
16   if (temp.length !== 0)
17     result.push(temp);
18   return result;
19 }

方法二：

 1 function chunk(arr, size) {
 2   // Break it up
 3   // It‘s already broken :(
 4   arr = arr.slice();
 5   var arr2 = [];
 6   for(var i = 0, len = arr.length; i < len; i+=size) {
 7     arr2.push(arr.slice(0, size));
 8     arr = arr.slice(size);
 9   }
10   return arr2;
11 }

方法三：

 1 function chunk(arr, size) {
 2   // Break it up.
 3   var newArr = [];
 4   var i = 0;
 5 
 6   while (i < arr.length) {
 7     newArr.push(arr.slice(i, i+size));
 8     i += size;
 9   }
10   return newArr;
11 }
12 chunk(["a", "b", "c", "d"], 2);

方法四：

 1 function chunk(arr, size) {
 2   // Break it up
 3   var newarr=[];
 4   
 5   for (var i=0;i<arr.length;i+=size){
 6     newarr.push(arr.slice(i,i+size));
 7   }
 8   return newarr;
 9 }
10 
11 chunk(["a", "b", "c", "d"], 2);