Javascript 当我使用getjson调用时，不会加载json数据

我正在用json数据绘制图表 我的控制器返回json数据

http://localhost:50418/json/index return 

json

在我看来，我试过这样做，它奏效了，所以问题不在于图表

var data = [],

    json = [{ "ID": 1, "name": "bob", "score": 212 }, { "ID": 2, "name": "alice", "score": 150 }];

for (var i = 0; i < json.length; i++) {
    data.push({
        name: json[i].name,
        id: json[i].ID,
        y: json[i].score
    });
}

---

如何将数据从控制器获取到变量json？？？

您知道必须将所有代码都放在回调中，对吗

$.getJSON("http://localhost:50418/json/index", function(response){
    json = response;
    var data = [],
    for (var i = 0; i < json.length; i++) {
        data.push({
            name: json[i].name,
            id: json[i].ID,
            y: json[i].score
        });
    }
});

// over here, json is undefined
// stuff here is executed before the getJSON actually gets the response...

---

打开Chrome Developer Tools，然后在Sources选项卡中找到脚本，并在函数中放置断点。

$.getJSON("http://localhost:50418/json/index", function(response){
       json = response;
  });

$.getJSON("http://localhost:50418/json/index", function(response){
    json = response;
    var data = [],
    for (var i = 0; i < json.length; i++) {
        data.push({
            name: json[i].name,
            id: json[i].ID,
            y: json[i].score
        });
    }
});

// over here, json is undefined
// stuff here is executed before the getJSON actually gets the response...