Question

我想将JavaScript对象分组为age.My JSON是

var jsonObj=[{"name":"john","age":23},{"name":"mark","age":25},{"name":"jeni","age":21}]`

我想成为这里的小组结果。

[23:{"name":"john","age":23},25:{"name":"mark","age":25},21:{"name":"jeni","age":21}]

请帮助我获得结果，我尝试map和filter，但没有得到结果。

Answer 1

使用Array#reduce对对象进行分组。因为可以有多个年龄相同的人，所以将他们收集到年龄属性下的数组中：

var jsonObj=[{"name":"john","age":23},{"name":"mark","age":25},{"name":"poll","age":23},{"name":"jeni","age":21}];

var result = jsonObj.reduce(function(r, o) {
  r[o.age] || (r[o.age] = []); // if the age key doesn't exist, set it to be an array
  
  r[o.age].push(o); // push the object into the array

  return r;
}, {});

console.log(result);

或花哨的ES6单线版：

var jsonObj=[{"name":"john","age":23},{"name":"mark","age":25},{"name":"poll","age":23},{"name":"jeni","age":21}];

var result = jsonObj.reduce((r, o) => ((r[o.age] || (r[o.age] = [])).push(o), r), {});

console.log(result);

Answer 2

您可以将哈希表作为结果。然后循环并为新键创建新数组。后来推动对象。

var data = [{ name: "john", age: 23 }, { name: "mark", age: 25 }, { name: "poll", age: 23 }, { name: "jeni", age: 21 }],
    result = {};

data.forEach(o => (result[o.age] = result[o.age] || []).push(o));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 3

您可以使用underscore js来解决此问题。
首先添加下划线js

<script src='https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore.js' ></script>
然后您只需获得结果。<登记/>
var result=_.indexBy(jsonObj, 'age');

Answer 4

你可以尝试一下：

var jsonObj = [{ "name": "john", "age": 23 }, { "name": "mark", "age": 25 }, { "name": "poll", "age": 23 }, { "name": "jeni", "age": 21 }];
let result = {};
jsonObj.forEach(item => {
    if(result.hasOwnProperty(item.age)) {
        let arr = [];
        if(Array.isArray(result[item.age])) {
            result[item.age].push(item);
        } else {
            result[item.age] = [result[item.age], item];
        }
    } else {
        result[item.age] = item;
    }
});
console.log(result)

如何在javaScript中使用特定键对对象进行分组

4 个答案: