在Javascript中合并和排序两个对象数组

时间:2017-12-27 19:48:35

标签: javascript arrays sorting

我有两个数组,根据元素在数组中的位置,它会收到一个值。两个数组都包含相同的元素,但位于不同的位置。我想计算每个元素的值,将数组合并到一个数组中,然后对新数组进行排序。

我能想到的唯一想法是将我的初始数组转换为对象数组,合并它们,按对象值排序,然后将该顺序映射到新数组中。

var ranks = [],
    objArray1 = [],
    objArray2 = [];

// 'aaa' = 5, 'bbb' = 4, 'ddd' = 3, 'eee' = 2, 'ccc' = 1
var array1 = ['aaa', 'bbb', 'ddd', 'eee', 'ccc'];

// 'ddd' = 5, 'ccc' = 4, 'aaa' = 3, 'bbb' = 2, 'eee' = 1
var array2 = ['ddd', 'ccc', 'aaa', 'bbb', 'eee'];

for (var i = 0, x = 5; i < 5; x--, i++) {
  var obj = {};
  obj[array1[i]] = x;
  objArray1.push(obj);
}

for (var i = 0, x = 5; i < 5; x--, i++) {
  var obj = {};
  obj[array2[i]] = x;
  objArray2.push(obj);
}

// combine both object arrays, match keys, but add values
// should output ranks =[{aaa: 8}, {bbb: 6}, {ccc: 5}, {ddd: 8}, {eee: 3}]

// then sort based on value
// should output ranks = [{aaa: 8}, {ddd: 8}, {bbb: 6}, {ccc: 5}, {eee: 3}]

// then copy keys over to new array while keeping position
// should output var final = ['aaa', 'ddd', 'bbb', 'ccc', 'eee']

2 个答案:

答案 0 :(得分:2)

你可以跳过带有对象的新临时数组的部分,只取一个对象进行计数,然后取出排序的键作为结果。

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var array1 = ['aaa', 'bbb', 'ddd', 'eee', 'ccc'],
    array2 = ['ddd', 'ccc', 'aaa', 'bbb', 'eee'],
    temp = Object.create(null),
    result;

[array1, array2].forEach(a => a.forEach((k, i) => temp[k] = (temp[k] || 0) - i));
result = Object.keys(temp).sort((a, b) => temp[b] - temp[a]);

console.log(result);
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答案 1 :(得分:1)

您可以使用reduce创建对象,然后在sort上使用Object.keys

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const array1 = ['aaa', 'bbb', 'ddd', 'eee', 'ccc'];
const array2 = ['ddd', 'ccc', 'aaa', 'bbb', 'eee'];
const n = array1.length;

const r = array1.reduce((r, e, i) => (r[e] = n - i + n - array2.indexOf(e), r), {})
const result = Object.keys(r).sort((a, b) => r[b] - r[a])
console.log(result)
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