Question

我知道.getJSON进行异步调用。这意味着我可以在for循环之后（因为.getJSON赢了）完成后，无法控制数组＆＃39;流#s;＆＃39; stream。但是，我的大多数Javascript取决于这些调用的结果！我认为这是承诺的来源。

但我真的需要等到所有.getJSON调用都是通过数组进行的，这意味着只将promise调用放在数组的最后一块（我想）。我应该怎么做呢，或者我是以错误的方式看待这个问题？感谢。

var reg_users = ["ESL_SC2", "OgamingSC2", "cretetion", "freecodecamp", "storbeck", "habathcx", "RobotCaleb", "noobs2ninjas"];
var streams = [];
for (var i = 0; i < reg_users.length; i++) {
  $.getJSON('https://api.twitch.tv/kraken/streams/' + reg_users[i] + '?callback=?', function(data) {
    streams.push(data);
  });
}

Answer 1

var reg_users = ["ESL_SC2", "OgamingSC2", "cretetion", "freecodecamp", "storbeck", "habathcx", "RobotCaleb", "noobs2ninjas"];
var reqs = [];
for (var i = 0; i < reg_users.length; i++) {
  reqs.push($.getJSON('https://api.twitch.tv/kraken/streams/' + reg_users[i] + '?callback=?'));
}

Promise.all(reqs).then((res) => {
  // do things with responses here.
});

Answer 2

这是一个解决方案。

var reg_users = ["ESL_SC2", "OgamingSC2", "cretetion", "freecodecamp", "storbeck", "habathcx", "RobotCaleb", "noobs2ninjas"];
var streams = [];
var promises = [];
for (var i = 0; i < reg_users.length; i++) {
  promises.push($.getJSON('https://api.twitch.tv/kraken/streams/' + reg_users[i] + '?callback=?'));
}

Promise.all(promises).then(function(all_data){
  // all_data is a list of response
  all_data.forEach(function(data){ 
    streams.push(data);
  });
});

如何在数组上调用.getJSON？

2 个答案: