SESSION returns old value when echoed in php

Question

<script language="javascript">
            function emergency()
            {
                if(document.getElementById('emer').checked == true)
                {
                    <?php $_SESSION['total2']= $_SESSION['total1'] + 50; ?>
                    document.getElementById('emr').innerHTML = "<b>Payable Amount: </b>" + <?php echo  $_SESSION['total2']; ?>;
                }
                if(document.getElementById('emer').checked == false)
                {
                    <?php $_SESSION['total2']= $_SESSION['total2'] - 50; ?>
                    document.getElementById('emr').innerHTML = "<b>Payable Amount: </b>" + <?php echo  $_SESSION['total2']; ?>;
                }
            }
            </script>

here I am adding $_SESSION['total1']+50 and put the value in new session SESSION['total2']. The problem is that , when I echo this new $_SESSION['total2'] out side script,ie, in the page like

<?php echo $_SESSION['total2'];?>

it returns the value of $_SESSION['total1']).

For sessions to work you need to reload the page using for example — Kees Sonnema, Mar 06 '14 at 10:41
Can you try `$_SESSION['total2'] = (int)$_SESSION['total1'] + 50;`? — vonUbisch, Mar 06 '14 at 10:41
you are doing +50 and -50 in total2 ... so no changes in total2 — user1844933, Mar 06 '14 at 10:42
Well, you first add 50, then you subtract 50? Or are you referring to first echo? — dkasipovic, Mar 06 '14 at 10:42
@vonUbisch@user1844933@D. Kasipovic@Nishant Solanki@user3383167:even if I change the code as $val= 30 + 50; and initialise a session outside script and then echo, the result is 30,ie, the first operand in the addition process. — Riyaz, Mar 06 '14 at 11:32
Maybe stupid but could happen; have you started the session using `session_start()`? — vonUbisch, Mar 06 '14 at 12:34
@vonUbisch: nice joke.....but not in a condition to laugh...sorry.. — Riyaz, Mar 06 '14 at 13:31
It wasn't my intention to joke, but to come to a solution for your problem. This has been easily forgotten many times here on SO. — vonUbisch, Mar 06 '14 at 13:35
@vonUbisch:sorry if it hurted you.But the problem is solved by using ajax call to set the session value....thank you all. — Riyaz, Mar 08 '14 at 06:44

Nishant Solanki · Accepted Answer · 2014-03-06T11:16:54.297

4

Are you calling a javascript function to change value of php session variable?.. this could not be possible because, php is a server side language and javascript is client side so php code gets executed when the page is loaded..

so if you want to do this on javascript function call,, than you need to use ajax...

edited Mar 06 '14 at 11:16

answered Mar 06 '14 at 10:56

Nishant Solanki

2,119
3
19
32

:now i just changed the code like $tot=$_SESSION['TOTAL1']+50 and outside javascript I initialized a session normally as $_SESSION['total2']=$tot .Then I echoed it. Still the same result. – Riyaz Mar 06 '14 at 11:27
the thing is that **you can not change php variable value using javascript**.. but by using `ajax` you can.. please refer this answer.. http://stackoverflow.com/questions/11540000/how-to-insert-javascript-value-into-the-php-session-variable – Nishant Solanki Mar 06 '14 at 11:41

score 1 · Answer 2 · answered Mar 06 '14 at 10:44

1

to get the new value of $_SESSION['total2'] you have to run the code on server side again. that means before getting the new value for total2 session variable you have to reload the appropriate php file.

answered Mar 06 '14 at 10:44

Janaka Dombawela

1,337
4
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:innerhtml displays correct values.but when i echo value anywhere else ,it returns session['total1'] value even after reloading the page. – Riyaz Mar 06 '14 at 11:08

SESSION returns old value when echoed in php

2 Answers2