JavaScript - 循环 JSON 数组并匹配子数组中的字符串

Question

我有带子数组的 JSON 数组，我想循环它并查找用户的用户名是否为“admin”。如果是，则创建包含属于用户“admin”(地区、运动、城市等)的数据的 JSON 数组。我不知道如何在循环中找到它然后切片。很抱歉提出愚蠢的问题，但我有点迷茫。

这是 JSON 数组，具有我所拥有的结构:

[
    {
        "_id": "5520f52e2c0a22541541bde1",
        "region": {
            "_id": "551e6779d8f1afa01bd86529",
            "name": "region_name"
        },
        "user": {
            "_id": "551a938af056a7fc099879c1",
            "firstName": "John",
            "lastName": "Boo",
            "username": "admin",
            "id": "551a938af056a7fc099879c1"
        },
        "__v": 0,
        "sport": [
            {
                "_id": "551e69c6d8f1afa01bd86533",
                "name": "Running"
            }
        ],
        "city": "some_city",
        "advert": "some_advert",
        "title": "I want to run!",
        "created": "2015-04-05T08:41:18.173Z"
    },
    {
        "_id": "552010740628cab002b3a700",
        "region": {
            "_id": "551e67b6d8f1afa01bd8652f",
            "name": "region_name"
        },
        "user": {
            "_id": "551a938af056a7fc099879c1",
            "firstName": "Bill",
            "lastName": "Foo",
            "username": "bill_foo",
            "id": "551a938af056a7fc099879c1"
        },
        "__v": 0,
        "sport": [
            {
                "_id": "551e5e01abb74a8423410b88",
                "nazev": "Hockey"
            }
        ],
        "city": "some_city",
        "advert": "some_advert",
        "title": "some_title",
        "created": "2015-04-04T16:25:24.733Z"
    }
]

编辑:用户“admin”的预期结果是:

[
    {
        "_id": "5520f52e2c0a22541541bde1",
        "region": {
            "_id": "551e6779d8f1afa01bd86529",
            "name": "region_name"
        },
        "user": {
            "_id": "551a938af056a7fc099879c1",
            "firstName": "John",
            "lastName": "Boo",
            "username": "admin",
            "id": "551a938af056a7fc099879c1"
        },
        "__v": 0,
        "sport": [
            {
                "_id": "551e69c6d8f1afa01bd86533",
                "name": "Running"
            }
        ],
        "city": "some_city",
        "advert": "some_advert",
        "title": "I want to run!",
        "created": "2015-04-05T08:41:18.173Z"
}]

Answer 1

遍历数组并提取用户名为 admin 的每个项目:

var result = [];
var nameToSearchFor = 'admin';

for(var index = 0; index < arr.length; index++)
{
    var item = arr[index];
    if(item.user.username === nameToSearchFor)
    {
        result.push(item);
    }
}