获取数组中对象在数组中对象的索引

Question

使用Impactjs，一个游戏引擎，这里和级别有一个非常奇怪的设置：

[
    {
       "entities": [
            {"type":"type1","x":100,"y":100,"settings":{"directsTo":"-5"}},
            {"type":"type2","x":101,"y":101,"settings":{"directsTo":"-4"}}
        ],
        "layer": [
            other data
         ]
    }
]

我想知道如何根据设置对象的directsTo属性来获取type1对象的索引？

Javascript或jQuery就可以了。

编辑:游戏必须在移动设备上流畅工作，所以有一个有效的解决方案是很好的。

Answer 1

尝尝这个,

var arr =[{
    "entities": [{
        "type": "type1",
        "x": 100,"y": 100,
        "settings": {"directsTo": "-5"}
    }, {
        "type": "type2",
        "x": 101,"y": 101,
        "settings": {"directsTo": "-4"}
    }],
    "layer": ['other data']
}];
var t='type1';
var newArr=arr[0];
for(var data in newArr){
    for(a in newArr[data]){
        if(newArr[data][a].type == t){
             alert('Index of '+t+' is '+a+' in '+data);
        }
    }
}

Live Demo

Updated demo

Answer 2

可以使用filter属性吗？

假设您的JS对象如下所示

var j = [
    {
       "entities": [
            {"type":"type1","x":100,"y":100,"settings":{"directsTo":"-5"}},
            {"type":"type2","x":101,"y":101,"settings":{"directsTo":"-4"}}
        ],
        "layer": [
            "otherdata":{}
         ]
    }
];

您可以使用以下命令查找对象

var result = j[0].entities.filter(function(n) { return n.settings.directsTo == "-5"; });
// result[0].type == "type1"

Answer 3

您可以创建一个函数，用于在其他对象中获取某个对象的索引，例如

//assuming you have the data parsed as a JSON object "data"
//and you also have your entity object as "obj"
function getIndex(obj, data){
    return data.entities.indexOf(obj);
}

如果没有"obj“对象，则必须创建一个函数，该函数首先根据属性查找正确的对象，例如type参数

function findEntity(type, source){
    for(var i=0; i<source.entities.length; i++){
        if(source.entities[i].type == type){
            return source.entities[i];
        }
    }
    return false;
}

现在你可以这样叫它

getIndex(findEntity("type1", data), data);

希望它能帮助你开始！