Setting the jQuery $.post return data to a JavaScript variable

Question

I have the following jQuery code in my HTML page:

$.post("MyPHP.php", {category: CATEGORY}, function(data){var test = data;});

But I can't seem to use test anywhere else in my page. I know this is AJAX so I have to wait for $.post to complete but the variable test is never set. If I instead use the return data to change the innerhtml of a paragraph, the paragraph updates after a small delay.

Any thoughts?

EDIT: Cracked it! You can call another function from the $.post return function, ie: function(data){setVar(data)}); and simply define the setVar(data) function as follows:

function setVar(data){test = data;}

Provided test has already been defined in global scope var test; you can use it through out the rest of your code.

Rafay · Accepted Answer · 2012-11-17 23:22:42Z

1

~~because the scope of your var is limited try moving your test variable to a much global scope~~

~~var test; $.post("MyPHP.php", {category: CATEGORY}, function(data){ test = data; });~~

ajax requests are asynchronous so you will never know when it is complete unless you put your variable in the success callback (which) you did or you can make the ajax request synchronous (plz dont do that) or you can use .when to make sure that your ajax call dependent code is executed when all the variables are set.

see this demo even if you move the test variable to the global scope it still logs undefined to the console so try

var test;
var x=$.post("MyPHP.php", {category: CATEGORY},, function(data){  
    test = data;   
});
console.log(test);// still undefined    
$.when( x ).then(function(args){
     console.log(test);// your var is set
});

http://jsfiddle.net/C4JnU/1/

edited Nov 17, 2012 at 23:22

answered Nov 17, 2012 at 21:03

Rafay

31.1k5 gold badges71 silver badges106 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

CptSpike Over a year ago

Thanks for all the replies, I tried this one and now the response I get for 'test' is undefined. I guess it's a problem with my php file, although it should only echo back an integer.

MrCode · Accepted Answer · 2012-11-17 21:04:01Z

0

You have declared your test variable within the ajax success function, therefore its scope is limited to the success function. If you want to access it from other code you can declare it in the global scope, and just overwrite it in the success function.

var test; // delcared in global scope

$.post("MyPHP.php", {category: CATEGORY}, function(data){ test = data;});

answered Nov 17, 2012 at 21:04

MrCode

64.6k10 gold badges95 silver badges114 bronze badges

Collectives™ on Stack Overflow

Setting the jQuery $.post return data to a JavaScript variable

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related