如何通过JSON和JavaScript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数据库的一个表。

"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"}]}

说我需要阅读“名称”键，其中Section = 1和Team = 2，Direction = N。

编辑：当然，我将使用js解析对象

Javascript的语法是什么？

Answer 1

我将假设您根本不处理JSON，而是处理从JSON 解析的对象树。 我将假设您给出的是对象定义的内容，例如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，在解析了JSON之后，您将拥有一个具有PlayerNumbers属性的对象，该对象引用具有PlayerNumber属性的对象，该对象引用具有所需信息的对象数组。

因此，您将遍历数组，直到找到第一个匹配的条目（假设您只想要第一个）：

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

如果您需要所有匹配项：

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

---

上面两种方法都使用Array ES5功能，而这些功能在过时的引擎上是缺少的。 如果您需要支持过时的引擎，则可以对上述所有内容进行“填充”或“填充”，搜索应查找必要的填充/填充。

Answer 2

var playersObject = { 
    "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"
    }]
    }
};

   function getParticularPlayer(section, team, direction) {
     return playersObject.PlayerNumbers.PlayerNumber.filter(function(player) {
            return (player.Section===section && player.Team===team && player.Direction===direction); 
     });
   }

现在，您可以使用

   var results = getParticularPlayer("1","1","N");

它将返回您匹配的玩家数组。 如果您确定总是只返回一名玩家，则可以使用results[0] 。