javascript - 如何暴力破解对象的值？

Question

我有一组具有数字坐标 (x,y) 和名称的对象。

我想对一个范围内的 x 和 y 的每个值强制 x 和 y。（说 [0,1,2,3,4,5]）

var variables = {"aboutTitle_x": 0, "aboutTitle_y": 0}
let f = (a, b) => [].concat(...a.map(a => b.map(b => [].concat(a, b))));
let cartesian = (a, b, ...c) => b ? cartesian(f(a, b), ...c) : a;


var candidates = cartesian(Object.keys(variables), [0, 1,2,3,4,5]);
console.log(candidates);

我正在使用笛卡尔积，这给了我每项任务，如下所示：

["aboutTitle_x", 0]
["aboutTitle_x", 1]
["aboutTitle_x", 2]
["aboutTitle_x", 3]
["aboutTitle_x", 4]
["aboutTitle_x", 5]
["aboutTitle_y", 0]
["aboutTitle_y", 1]
["aboutTitle_y", 2]
["aboutTitle_y", 3]

我如何迭代（aboutTitle_x，aboutTitle_y）的潜在组合。我想要的是这样的东西：

{aboutTitle_x: 0, aboutTitle_y: 0}
{aboutTitle_x: 0, aboutTitle_y: 1}
{aboutTitle_x: 0, aboutTitle_y: 2}
{aboutTitle_x: 0, aboutTitle_y: 3}
{aboutTitle_x: 0, aboutTitle_y: 4}

标签： javascript

Answer 1

您可以使用递归方法，for在值上使用循环，但使用递归递增键，并且还可以将对象引用作为当前值传递。

var variables = {
  "aboutTitle_x": 0,
  "aboutTitle_y": 0
}

function cartesian(keys, values, k = 0, tmp = {}) {
  const r = [];

  if (k >= keys.length) {
    r.push({ ...tmp });
    return r;
  }

  for (let i = 0; i < values.length; i++) {
    Object.assign(tmp, {[keys[k]]: values[i]})
    r.push(...cartesian(keys, values, k + 1, tmp))
  }

  return r;
}


var candidates = cartesian(Object.keys(variables), [0, 1, 2, 3, 4, 5]);
console.log(candidates);

您也可以使用reduce方法而不是for循环来执行此操作。

var variables = {
  "aboutTitle_x": 0,
  "aboutTitle_y": 0
}

function cartesian(keys, values, k = 0, tmp = {}) {
  return values.reduce((r, e) => {
    tmp[keys[k]] = e;

    if (k >= keys.length - 1) {
      r.push({ ...tmp});
      return r;
    }

    r.push(...cartesian(keys, values, k + 1, tmp))
    return r;
  }, [])
}


var candidates = cartesian(Object.keys(variables), [0, 1, 2, 3, 4, 5]);
console.log(candidates);

您还可以将递归与生成器一起使用，这将使您能够控制每次迭代。

var variables = {
  "aboutTitle_x": 0,
  "aboutTitle_y": 0
}

function* cartesian(keys, values, k = 0, tmp = {}) {
  if (k >= keys.length) {
    yield { ...tmp }
  } else {
    for (let i = 0; i < values.length; i++) {
      Object.assign(tmp, { [keys[k]]: values[i] })
      yield* cartesian(keys, values, k + 1, tmp)
    }
  }
}

var it = cartesian(Object.keys(variables), [0, 1, 2, 3, 4, 5]);

for (let i of it) {
  console.log(i)
}