javascript - 按数组属性的长度对 JavaScript 对象进行排序

Question

我有一个这样的对象：

var list = {
  "you": [100,200,300], 
  "me": [75,4,5,6,8,9], 
  "foo": [116,345,1,23,56,78], 
  "bar": [15,34]
};

有没有办法sort通过数组属性的长度来处理这个对象？

预期输出：

var res =  [[116,345,1,23,56,78],[75,4,5,6,8,9],[100,200,300],[15,34]]

我尝试使用 lodash 的sortby功能。

var data = {
  "abc": ["20288", "d8f0", "4a5d", "1a8a0"],
  "kkl": ["bnb", "lll", "zxc"],
  "F17": ["ee547", "42e9"],
  "cnv": ["20288", "d8f0", "4a5d", "1a8a0", "jh67"]
}

var res = _.sortBy(data, function(val) {
  return parseInt(val.length);
});

console.log(res);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

标签： javascriptarrayssortingjavascript-objects

Answer 1

1. 如果要将输出作为排序数组值的数组：

   使用解构赋值length通过调用从结果数组中获取属性Object.values，然后按降序对其进行排序。

const data = {
  "abc": ["20288", "d8f0", "4a5d", "1a8a0"],
  "kkl": ["bnb", "lll", "zxc"],
  "F17": ["ee547", "42e9"],
  "cnv": ["20288", "d8f0", "4a5d", "1a8a0", "jh67"]
};
const res = Object.values(data).sort(({length:a}, {length:b}) => b - a);
console.log(res);

---

2. 如果您想通过根据数组值的长度重新排列键来对对象本身进行排序。

   有没有办法按数组属性的长度对这个对象进行排序？

   如果要根据length数组值重新排列原始对象属性，那么我们首先需要按键排序，然后使用键的排序顺序创建一个新 对象Array.reduce。

const data = {
  "abc": ["20288", "d8f0", "4a5d", "1a8a0"],
  "kkl": ["bnb", "lll", "zxc"],
  "F17": ["ee547", "42e9"],
  "cnv": ["20288", "d8f0", "4a5d", "1a8a0", "jh67"]
};
//sorting in descending order
const obj = Object.keys(data)
                  .sort((a, b) => data[b].length - data[a].length )
                  .reduce((acc, ele) => { acc[ele] = data[ele]; return acc; }, {});

console.log(obj);