如何从单一阵列创建数组的集合？ [英] How do I create a collection of arrays from a single array?

问题描述

说我有一个大阵像

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]

和想将其分成n元组的数组像

and would like to split it into an array of n-tuples like

[[1,2], [3,4], [5,6], [7,8], [9,10], [11,12], [13,14] /*, ... */ ] // (for n=2)

有一些简单的方法来实现这一目标？特殊情况下， N = 2 会为我足够了。

Is there some easy way to achieve this? The special case n = 2 would be enough for me.

推荐答案

这应该工作：

for (var i=0; i<arr.length; i+=2) {
  result.push([arr[i], arr[i+1]]);
}

想出了这个，就应该适用于任何数量无论你想打电话给他们钱袋或。它检查未定义所以它适用于奇数的项目：

Came up with this, it should work for any number of "pockets" or whatever you want to call them. It checks for undefined so it works with odd number of items:

Array.prototype.pockets = function(n) {

  var result = [],
      pocket = [],
      i, j;

  for (i=0; i<this.length; i+=n) {
    pocket.length = 0;
    for (j=1; j<n; j++) if (this[i+j] != null) pocket.push(this[i+j]);
    result.push([this[i]].concat(pocket));
  }

  if (arguments.length > 1) {
    return result.pockets.apply(result, [].slice.call(arguments,1));
  }

  return result;
};

// Usage:
var arr = [1,2,3,4,5,6,7,8,9,10,11];

arr.pockets(2); //=> [[1,2],[3,4],[5,6],[7,8],[9,10],[11]]
arr.pockets(3); //=> [[1,2,3],[4,5,6],[7,8,9],[10,11]]

// Recursive:
arr.pockets(1,3); //=> [ [[1],[2],[3]], [[4],[5],[6]], [[7],[8],[9]], [[10],[11]] ]

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