javascript - 以两个为增量解构数组

Question

假设我有一个这样的数组:

let arr = [1, 2, 3, 4, 5, 6, "a"]

我怎样才能将它解构为以两个为增量的单个变量？那么 let one = [1, 2], let two = [3, 4] 等等？我知道您可以像这样使用单个变量来解构数组:

let one, two, three;
[one, two, three] = arr

但是以两个为增量进行，这可能吗？

Answer 1

另一种方法是通过 ES6 generator function :

let arr = [1, 2, 3, 4, 5, 6, 'a']

function* batch (arr, n=2) {
  let index = 0
  while (index < arr.length) {
    yield arr.slice(index, index + n)
    index += n
  }
}

let [first, second, third] = batch(arr)

console.log(first)
console.log(second)
console.log(third)

或者更通用的方法，如 @Patrick Roberts 所建议的那样:

let arr = [1, 2, 3, 4, 5, 6, 'a']

function* batch (iterable, length=2) {
  let array = [];
  for (const value of iterable) {
    if (array.push(value) === length) {
      yield array;
      array = [];
    }
  }
  if (array.length) yield array;
}

let [first, second, third] = batch(arr);

console.log(first)
console.log(second)
console.log(third)

最后是 curried版本:

let arr = [1, 2, 3, 4, 5, 6, 'a']

const batch = length => function* (iterable) {
  let array = [];
  for (const value of iterable) {
    if (array.push(value) === length) {
      yield array;
      array = [];
    }
  }
  if (array.length) yield array;
}

let [first, second, third] = batch(2)(arr);

console.log(first)
console.log(second)
console.log(third)