循环使用具有特定参数的对象数组(Looping through a object array with specific parameters)

 我需要准确地遍历我的json数组以匹配位置和d3对象id的id。 
 
 这是一个数组的片段（生成的rails上的ruby）： 
 
{
    "name": "Test",
    "locations": [{
        "city_id": 1,
        "x": 0,
        "y": 0
        }, {
        "city_id": 2,
        "x": 0,
        "y": 0
        }, {
        "city_id": 3,
        "x": 0,
        "y": 0
        }, {
        "city_id": 118,
        "x": 0,
        "y": 0
        }, {
        "city_id": 117,
        "x": 0,
        "y": 0
        }, 
    ],
    "city": [{
        "id": 118,
        "name": "London"
        }, {
        "id": 117,
        "name": "New York"
        }, {
        "id": 1,
        "name": "Miami"
        }, {
        "id": 3,
        "name": "Duabi"
        }, {
        "id": 2,
        "name": "Hong Kong"
        }
    ]
}
 
 收集x＆yi的值具有拖放功能。 当一个对象我发送一个帖子来更新x和y值的位置时。 但是，它将更新发送到正确的id，因为我的循环不够具体。 
 
 所以现在我必须找到一种方法来收集城市位置并将它们与d3对象/城市匹配。所以我像这样循环： 
 
   .attr("transform", function(d,i) {return "translate("+json.locations[i].x+","+json.locations[i].y+")" ;})
 
 但这只是通过数组而没有匹配任何东西。 所以我想基本上我的循环通过＆看看id是否相关，然后将该位置分配给相关的d3对象。 因此，如果城市ID：118被拖放，则位置city_id：188应该更新而不是city_id：1这是问题所在。 
 
 这可能吗。 
 
 提前致谢 

I need to accurately loop through my json array to match ids of positions and d3 objects ids. 
 
Here's a snippet of the array (ruby on rails generated): 
 
{
    "name": "Test",
    "locations": [{
        "city_id": 1,
        "x": 0,
        "y": 0
        }, {
        "city_id": 2,
        "x": 0,
        "y": 0
        }, {
        "city_id": 3,
        "x": 0,
        "y": 0
        }, {
        "city_id": 118,
        "x": 0,
        "y": 0
        }, {
        "city_id": 117,
        "x": 0,
        "y": 0
        }, 
    ],
    "city": [{
        "id": 118,
        "name": "London"
        }, {
        "id": 117,
        "name": "New York"
        }, {
        "id": 1,
        "name": "Miami"
        }, {
        "id": 3,
        "name": "Duabi"
        }, {
        "id": 2,
        "name": "Hong Kong"
        }
    ]
}
 
To collect the values of x & y i have a drag & drop functionality. When a drop an object i send off a post to update the positions of x & y values. However, it sends the update to in correct id as my loop isnt specific enough.
 
So now I have to find a way to collect the city locations & match them with d3 objects/cities.So I looped through like this: 
 
   .attr("transform", function(d,i) {return "translate("+json.locations[i].x+","+json.locations[i].y+")" ;})
 
But this just goes through the array without matching anything. So I would like essentially my loop to go through & to see if the ids correlate & then assign that location to the relevant d3 object. So if city id: 118 is dragged & dropped the location city_id:188 should update not city_id:1 which is the problem.
 
Is this possible.
 
thanks in advance

原文：https://stackoverflow.com/questions/17328555