按属性数组对对象数组进行排序答案

【问题标题】：Sorting an array of objects by property array按属性数组对对象数组进行排序
【发布时间】：2019-12-17 13:27:01
【问题描述】：

我得到了一组像这样的对象：

var SkillBuddys = [
    {
        Property1: "1",
        Property2: "Test",
        Property3: "Data",
        Property4: [{},{},{}],
    }, {
        Property1: "2",
        Property2: "Test2",
        Property3: "Data2"
    }, {
        Property1: "3",
        Property2: "Test3",
        Property3: "Data3",
        Property4: [{},{}],
    }, {
        Property1: "4",
        Property2: "Test4",
        Property3: "Data4"
    }, {
        Property1: "5",
        Property2: "Test5",
        Property3: "Data5",
        Property4: [{}],
    }
];

我想在属性 4 上使用 javaScript 对其进行排序，所以如果对象具有属性 4 并包含一个数组。像这样：

var SkillBuddys = [
    {
        Property1: "1",
        Property2: "Test",
        Property3: "Data",
        Property4: [{},{},{}],
    }, {
        Property1: "3",
        Property2: "Test3",
        Property3: "Data3",
        Property4: [{},{}],
    }, {
        Property1: "5",
        Property2: "Test5",
        Property3: "Data5",
        Property4: [{}],
    }, {
        Property1: "2",
        Property2: "Test2",
        Property3: "Data2"
    }, {
        Property1: "4",
        Property2: "Test4",
        Property3: "Data4"
    }
];

如果属性 4 不存在，则返回“未定义”。如何使用 Array.Sort 对其进行排序？

【问题讨论】：

标签： javascript arrays sorting

【解决方案1】：

您可以使用length 属性和|| 运算符来sort 数组。

var array = [ { Property1: "1", Property2: "Test", Property3: "Data", Property4: [{},{},{}], }, { Property1: "2", Property2: "Test2", Property3: "Data2" }, { Property1: "3", Property2: "Test3", Property3: "Data3", Property4: [{},{}], }, { Property1: "4", Property2: "Test4", Property3: "Data4" }, { Property1: "5", Property2: "Test5", Property3: "Data5", Property4: [{}], } ];

array.sort((a, b) => (b['Property4'] || []).length - (a['Property4'] || []).length);

console.log(array);

【讨论】：

【解决方案2】：

如果属性不存在，一种方法可能是解构然后使用默认数组。然后您可以通过数组长度的差异.sort()：

const skillBuddys = [ { Property1: "1", Property2: "Test", Property3: "Data", Property4: [{},{},{}], }, { Property1: "2", Property2: "Test2", Property3: "Data2" }, { Property1: "3", Property2: "Test3", Property3: "Data3", Property4: [{},{}], }, { Property1: "4", Property2: "Test4", Property3: "Data4" }, { Property1: "5", Property2: "Test5", Property3: "Data5", Property4: [{}], } ];

const res = skillBuddys.sort(
  ({Property4: a = []}, {Property4: b = []}) => b.length - a.length
);

console.log(res);

【讨论】：

【解决方案3】：

SkillBuddys
.filter((x) => Array.isArray(x.Property4)  )
.sort( (a,b) => b.Property4.length - a.Property4.length)
.concat( SkillBuddys.filter((x) => !Array.isArray(x.Property4))

这将为您提供一个数组，其中包含 Property4 的元素按内部数组的长度排序，然后其余元素没有指定的顺序（您可以使用您选择的顺序来管道排序（））

【讨论】：