Question

我有两个这样的对象数组

var array1 = [
  {
   "key": 0,
   "display": "hide",
  },
  {
   "key": 1,
   "display": "show",
  },
  {
   "key": 2,
   "display": "show",
  },
 ]

var array2 = [
 {
  "key": 1,
  "question": "some text here",
 },
 {
  "key": 0,
  "question": "Different text here",
 },
 {
  "key": 2,
  "question": "Even more different",
 },
]

我需要重新排序array1以匹配array2中键的顺序，而不仅仅是更新键以匹配顺序，但显示值需要更新（因此移动/重新排序整个对象）

例如，在对array1进行排序以匹配array2键的顺序后，我希望array1导致：

[
 {
  "key": 1,
  "display": "show",
 },
 {
  "key": 0,
  "display": "hide",
 },
 {
  "key": 2,
  "display": "show",
 }
]

我知道这可能是使用sort函数完成的，但是我很难理解它在这种情况下是如何工作的。

Answer 1

您可以创建一个hashMap，它将保存索引值，并根据它来排序数组。

var array1 = [ { "key": 0, "display": "hide", }, { "key": 1, "display": "show", }, { "key": 2, "display": "show", },]

var array2 = [ { "key": 1, "question": "some text here", }, { "key": 0, "question": "Different text here", }, { "key": 2, "question": "Even more different", },]

var array2Hash = array2.reduce(function(p,c,i){
  p[c.key] = i;
  return p;
}, Object.create(null))

array1.sort(function(a,b){
  return array2Hash[a.key] - array2Hash[b.key];
});

console.log(array1);

Answer 2

您可以通过以下方式实现这一目标：

var array1 = [ { "key": 0, "display": "hide", }, { "key": 1, "display": "show", }, { "key": 2, "display": "show", }];
var array2 = [ { "key": 1, "question": "some text here", }, { "key": 0, "question": "Different text here", }, { "key": 2, "question": "Even more different", }];

var keys = array2.map(el => el.key);
array1.sort((a, b) => keys.indexOf(a.key) - keys.indexOf(b.key));
console.log(array1);

Answer 3

我可能通过构建第一个数组索引的键映射来接近它，然后在排序第二个数组时使用该映射，请参阅注释：

＆＃13;

var array1 = [ { "key": 0, "display": "hide", }, { "key": 1, "display": "show", }, { "key": 2, "display": "show", },]

var array2 = [ { "key": 1, "question": "some text here", }, { "key": 0, "question": "Different text here", }, { "key": 2, "question": "Even more different", },]

// Build the map of key->index from the first array
var map = Object.create(null);
array1.forEach(function(entry, index) {
  map[entry.key] = index;
});
// Sort the second array using the key->index map
// map[left.key] - map[right.key] returns a number less than 0
// if the left should be before the right, 0 if they're the
// the same (they won't be, as these are indexes from the
// first array), or greater than zero if the left should be
// after the right
array2.sort(function(left, right) {
  return map[left.key] - map[right.key];
});
console.log(array2);

＆＃13;

.as-console-wrapper {
  max-height: 100% !important;
}

＆＃13;

两个对象数组，需要根据另一个对象进行排序

3 个答案: