Javascript-如何将项目分配到嵌套数组中，例如发牌？

Question

这似乎很简单，但我无法正常工作。我想做的是从数组中获取项目，并将它们一个一地分发到嵌套数组中。这是我的代码：

    const numbers = [1, 2, 3, 4, 5, 6, 7, 8]

    const nestedArray = Array(numberOfSlots).fill([])

    _.forEach(numbers, (number, index) => {
      console.log('index', index);
      nestedArray[index % numberOfSlots].push(number)
      console.log('nested Array', nestedArray)```


What I expected to see was something like this:

iteration 1: `[[1][][][][]`
iteration 2: `[[1][2][][][]`
iteration 3: `[[1][2][3][][]`
iteration 4: `[[1][2][3][4][]`
iteration 5: `[[1][2][3][4][5]`
iteration 6: `[[1, 6][2][3][4][5]`
iteration 7: `[[1, 6][2, 7][3][4][5]`
iteration 8: `[[1, 6][2, 7][3, 8][4][5]`

but what I get is this:

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/xYH2m.png

Why is this happening? As best I can tell it adds every item to every sub-array on each pass instead of only the array index I'm trying to push it to. How can I fix it?

Answer 1

您的问题是，顶层数组中的每个元素都是内存中同一数组的引用，从而导致您遇到的行为。解决此问题的一种方法是使用map数组方法，以确保用内存中的唯一对象填充顶级数组中的每个元素。

const numberOfSlots = 5;

const numbers = [1, 2, 3, 4, 5, 6, 7, 8]

const nestedArray = Array(numberOfSlots)
  .fill(null)
  .map(() => new Array());

numbers.forEach((number, index) => {
 nestedArray[index % numberOfSlots].push(number)
})

console.log('nested Array', nestedArray)