Twitch API Ajax call

JavaScript
1

Hello, I have been searching everywhere, but have not figured this out. Basically, I have been trying to update a global variable from within my ajax call. My ajax call is trying to update an array I have created of both online and offline streamers when going through an if-else statement to check for which streamer is online. The problem is that my global variables are returning in the console “TypeError: offline/online is undefined”. Perhaps a snippet of my code can clarify a bit better:

$(document).ready(function() {

  var online, offline;
  var streamers = ["ninja", "freecodecamp", "summit1g", "TimTheTatman", "CDNThe3rd"];

  $('#online').click(function() {
    setOnlineOffline();
    console.log(online);
  });

  $('#offline').click(function() {
    setOnlineOffline();
    console.log(offline);
  });

 function setOnlineOffline() {
        for (var i = 0; i < streamers.length; i++){
          url = 'https://wind-bow.gomix.me/twitch-api/streams/' + streamers[i];
        $.ajax({
          type: 'GET',
          url: url,
          dataType: 'jsonp',
          success: function(data) {
              if (data.stream !== null){
                online.push(streamers[i]);
              }
              else {
                offline.push(streamers[i]);
              }
          },
          error: function(errorMessage){
          alert("Error")
        }
        });
      };
    }
});
2

Same issue as this: Need help with my for loop (Twitch API project)