javascript - 如何使用 javascript 从 JSON 访问单个对象？

Question

我有一个 JSON 列表，该列表来自具有多个同级的数据库中的表。

"PlayerNumbers":{"PlayerNumber":[
{"Section":"1","Team":"1","Direction":"N","Number":"00280149","Name":" ANSART A","Updated":"False","TimeLog":"","Processed":"False"},
{"Section":"1","Team":"1","Direction":"S","Number":"00280131","Name":"ANSART Y","Updated":"False","TimeLog":"","Processed":"False"},
{"Section":"1","Team":"2","Direction":"N","Number":"01964990","Name":" LAHAYE B","Updated":"False","TimeLog":"","Processed":"False"}]}

假设我需要读取“名称”键，其中部分 = 1，团队 = 2，方向 = N。

编辑:当然我会使用 js 解析对象

Javascript 的语法是什么？

Answer 1

我假设您根本不处理 JSON，而是处理从 JSON 解析的对象树。我假设您给出的是对象定义的内容，如以下 JSON:

{
    "PlayerNumbers": {
        "PlayerNumber": [
            {
                "Section": "1",
                "Team": "1",
                "Direction": "N",
                "Number": "00280149",
                "Name": " ANSART A",
                "Updated": "False",
                "TimeLog": "",
                "Processed": "False"
            },
            {
                "Section": "1",
                "Team": "1",
                "Direction": "S",
                "Number": "00280131",
                "Name": "ANSART Y",
                "Updated": "False",
                "TimeLog": "",
                "Processed": "False"
            },
            {
                "Section": "1",
                "Team": "2",
                "Direction": "N",
                "Number": "01964990",
                "Name": " LAHAYE B",
                "Updated": "False",
                "TimeLog": "",
                "Processed": "False"
            }
        ]
    }
}

因此，解析 JSON 后，您将获得一个具有 PlayerNumbers 属性的对象，该对象引用具有 PlayerNumber 属性的对象，该属性引用一个数组包含您想要的信息的对象。

因此，您循环遍历数组，直到找到第一个匹配的条目(假设您只需要第一个):

var name;
obj.PlayerNumbers.PlayerNumber.some(function(entry) {
    if (entry.Section == "1" && Team == "2" && entry.Direction == "N") {
        name = entry.Name;
        return true;
    }
    return false;
});

如果您想要所有匹配项:

var names = obj.PlayerNumbers.PlayerNumber.filter(function(entry) {
    return (entry.Section == "1" && Team == "2" && entry.Direction == "N");
}).map(function(entry) { return entry.Name; });

<小时/>

以上两者都使用过时引擎上缺少的 Array 的 ES5 功能。如果您需要支持过时的引擎，以上所有内容都可以“填充”或“填充”，搜索应该会找到必要的填充/填充。