AJAX not saving variables to javascript (asynchronous issues)

Question

Why is alert saying that the text[0] is undefined?

This is my code:

var text = new Array;
$.ajax({
   url: 'engine1/api.php', 
   data: "", 
   dataType: 'json', 
   success: function(rows){
      text = rows;
   } 
});
alert(text[0]);

Ronan Thibaudau · Accepted Answer · 2016-08-21 02:29:20Z

1

var text = new Array;
$.ajax({
   url: 'engine1/api.php', 
   data: "", 
   dataType: 'json', 
   success: function(rows){
      text = rows;
      alert(text[0]); // will work, this gets executed after you set text
   } 
});
//alert(text[0]); << don't put this here, it will get executed right after you send the request

answered Aug 21, 2016 at 2:29

Ronan Thibaudau

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Artur Grigio · Accepted Answer · 2016-08-21 02:25:45Z

0

Finally answered my own question, for anyone that comes across this question, here is what I did:

Because ajax is asynchronous, alert(text[0]) is getting executed before text=rows.

You can set ajax to run procedurally like this:

$.ajax({ url: 'engine1/api.php', data: "", dataType: 'json', async: false; success: function(rows){...

Apperently this is one of the few cases that you can/should set ajax to async:false (because you're serving javascript/jquery to the client).

edited Aug 21, 2016 at 2:25

answered Nov 7, 2014 at 1:19

Artur Grigio

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1 Comment

Ronan Thibaudau Over a year ago

there's no reason to remove async, the alert should just be in the onsuccess continuation

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