Question

我只能使用来自JSON响应的数据但是当我尝试使用本地存储的数组数据以防JSON响应为null时，数组值变为未定义...具体，如果JSON的响应包含 null我希望显示存储的数组名称，以便我可以检测到它。请看一下我的代码：

$(document).ready(function() {

    var baseUrl = "https://wind-bow.glitch.me/twitch-api/streams/";
    var streamers = ["ESL_SC2", "OgamingSC2", "cretetion", "freecodecamp", "storbeck", "habathcx", "RobotCaleb", "noobs2ninjas"];

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

    var url = baseUrl+streamers[i];
    $.getJSON(url,function(data){
        if (data.stream === null){
    alert(streamers[i]+" is offline"); //<< this becomes undefined 
        }
        else {
    $('.stream').prepend(
    "<tr><td>" + data.stream.channel.display_name + " Channel   <strong class='connection'>ONLINE</strong> <div class='desc'><p>now streaming"+ data.stream.channel.status+" </p></div> </td></tr>");
    alert(data.stream.channel.display_name + " is streaming "); // <<< this works
    }
});

}

}）;

Answer 1

尝试使用函数将响应传递给它：

＆＃13;

var baseUrl = "https://wind-bow.glitch.me/twitch-api/streams/";
var streamers = [
  "ESL_SC2",
  "OgamingSC2",
  "cretetion",
  "freecodecamp",
  "storbeck",
  "habathcx",
  "RobotCaleb",
  "noobs2ninjas"
];

function streamToTable(stream) {
  $.getJSON(baseUrl + stream, function(data) {
    var TR = "";
    if (data.stream === null) {
      TR = "<tr><td>" + stream + "</td><td>OFFLINE</td></tr>"
    } else {
      TR = "<tr><td>" + data.stream.channel.display_name + " Channel </td><td><strong class='connection'>ONLINE</strong> <div class='desc'><p>now streaming " + data.stream.channel.status + " </p></div></td></tr>";
    }
    $('.stream').prepend(TR);
  });
}

$(document).ready(function() {
  streamers.map(streamToTable);
});

＆＃13;

td{border-bottom: 1px solid #ddd; vertical-align:top;}

＆＃13;

<table class="stream"></table>


<script src="https://code.jquery.com/jquery-3.1.0.js"></script>

＆＃13;

使用$ .getJSON方法获取＆＃39; undefined＆＃39;值

1 个答案: