JSON使用node.js循环多维数组

Question

Having read up on different methods please bear with me to try to explain.

I am trying to retreive data from the twitch api and loop the user.name results to an array possibly inside an object. I am using nodejs so it has to be javascript.

So far when I run the following I get a nice json response.

var request = require('request');

    request({url: 'https://api.twitch.tv/kraken/channels/twitch/follows?limit=3'}, function(err, res, json) {
        if (err) {
            throw err;
        }

        console.log(json);

    });

this then logs the same as if one where to visit https://api.twitch.tv/kraken/channels/twitch/follows?limit=3

or better visualized as

Now I want to select the follows -> user -> name object. More so, loop every user -> name in the response.

I thought I would need to convert the string to an object so I tried

    var obj = JSON.parse(json);

but that only returns the first {3} objects in the tree. So I went ahead and tried

var request = require('request');

    request({url: 'https://api.twitch.tv/kraken/channels/twitch/follows?limit=3'}, function(err, res, json) {
        if (err) {
            throw err;
        }

        for (var i=0; i<json.length; i++) {

        var obj = JSON.parse(json.follows[i].user.name);
        console.log(obj);

        }

    });

and it returns

TypeError: Cannot read property '0' of undefined

For testing purposes I also got rid of the loop and just have 1 to return one bit of info. Having tried multiple instances of rearranging the call I always get either an error or "undefined" back.

Nothing seems to work, I am even going about this the right way?

Answer 1

循环遍历json.followers.length而不是json.length - json是一个对象，并且对象没有长度：

for (var i=0; i<json.follows.length; i++) {

Answer 2

As json is an object here, we should use for-in though there is no length property. But here json.follows is an array. So we should use for loop.

var len = json.follows.length;
for (var i=0; i< len; i++) {
    console.log(json.follows[i].user.name);
}

Answer 3

Supposing you do var obj = JSON.parse(json);

for (var j = 0; j < obj.follows.length; j++) {
    var thisName = jsonObj.follows[j].user.name;
    console.log(thisName);
}