javascript - 使用 d3.json() 访问嵌套 JSON

Question

我有以下 JSON

{
    "users":
 {
     "gender":
  {
      "tot":
   [
       {"label":"female", "value":6038},
       {"label":"male", "value":45228},
       {"label":"unknown", "value":32932}
   ]
  }
 }
}

我可以使用d3.json()加载文件并通过console.log()将其可视化，但我无法访问内部值和标签

请考虑以下脚本

d3.json("../data/m5s/sumStats.json", function(data) {
    console.log(data)
    x.domain(data.map(function(d) {
        return d[0].users[0].gender[0].comment[0].label;
    }));
});

在第三行返回

Uncaught TypeError: undefined is not a function 

Answer 1

您可以以普通对象表示法访问数据:

d3.json("../data/m5s/sumStats.json", function(data) {
    // these are just examples, you don't need them
    console.log(data);
    console.log(data.users);
    console.log(data.users.gender);
    console.log(data.users.gender.tot);

    // this is the important bit: we're not going over 'data' but over a sub-object of data:
    x.domain(data.users.gender.tot.map(function(d) { return d.label; }));
});