How to access php session data inside template files jquery code - php

Question

I have ajax that calls a php file called "fetch_quarter_limit.php" from template file.
$.ajax({
type: 'POST',
url: 'fetch_quarter_limit.php',
data: {
leavefrom: from,
leaveto: to,
empid: emp
},
success: function(data) {
var quarter_limit = data['myVar'];
alert(quarter_limit);
}
});
In my .php file i have tried to return the session data as an array.
Fetched the required data, stored in session and formed an array.
$_SESSION['quarter_limit_mend'] = $quarterLimit;
$returnVal = array('myVar' => $_SESSION['quarter_limit_mend']);
echo $returnVal;
As shown in above ajax code part, i tried to fetch it, but all i am getting is "undefined" when i output the variable using alert.
Please help.
Ajax code updated, p2 :
Adding dataType is making code not to work.
$.ajax({
type: 'POST',
url: 'fetch_quarter_limit.php',
dataType: 'json',
data: {
leavefrom: from,
leaveto: to,
empid: emp
},
success: function(data) {
alert(data);
}
});
As #Tim mentioned i have added custom json encode function to my .php file.
It returns as expected {"myVar": 2}
echo array_to_json($returnVal);
This is returned from php file.
But not able to access in ajax code.

Answer 1

You're using echo on an array, which is not possible. As described in the PHP manual
echo outputs one or more strings.
Usually you'd use json_encode() on your array and then output it to the screen. But as you've commented you are using php < 5. First of all, if possible, you should consider to upgrade to PHP > 7, as this not only improves performance, it also improves security.
If you can't upgrade to a PHP version above PHP 5, then you can use workarounds. On this question there is already an answer for the workaround, and the workaround can be found on the PHP manual itself.
You should be able to use the returned JSON data.

Answer 2

Reply for after your edit
So you have your data as JSON now, but JS will still see it as a string. In your success function you still have to parse it.
success: function(data) {
jsonData = JSON.parse(data);
alert(jsonData.myVar);
}
I do have to add too that it is very insecure to continue using php < 7.3 (as of today, 24-02-2021)