How to store the value of a javascript variable into php variable?

Question

I need to pass a value from javascript to php. How can i achieve this since one runs on client side and other on server? or any other alternatives for this to happen? I am a newbie in programming, so correct and suggest me if i am wrong.

<html> 
    <head>
       <SCRIPT language="JavaScript"> 

          var q1=Math.floor(Math.random()*11) 
          <?php 
             $ff =  q1; 
          ?>
       </SCRIPT> 

    </head> 

    <body> 
       <?php 
          echo $ff ; 
       ?> 
    </body> 
</html>

PHP runs on the server to create the page. It's all done by the time Javascript runs on the client. — Barmar
– Barmar, Commented Jan 12, 2014 at 7:10
If you need to pass data from Javascript to PHP, you have to submit a form or use AJAX. — Barmar
– Barmar, Commented Jan 12, 2014 at 7:11
Is my code wrong. If not, why am nt i able to pass the value from JS to php? — user3180745
– user3180745, Commented Jan 12, 2014 at 7:12

Dev01 · Accepted Answer · 2014-01-12 07:20:04Z

3

It is not possible since PHP code (server-side) is run/parsed before javascript code (client side). So what you are doing is not possible although reverse is possible. You can also use:

Ajax
Hidden form field
Query string variable (via url)

To send javascipt variable value to php.

edited Jan 12, 2014 at 7:20

answered Jan 12, 2014 at 7:12

Dev01

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1 Comment

user3180745 Over a year ago

So , its not at all possible to pass the javascript variable to PHP. Can i store value of Q1 in a database(sql)? If so please suggest how?

Girish · Accepted Answer · 2015-06-05 11:19:31Z

2

PHP is server side language, that is used to render output in HTML, so you can assign PHP variable in JavaScript variable not JavaScript to php, you can send JavaScript variable to Server by AJAX

Try this way

<SCRIPT language="JavaScript"> 
var q1=Math.floor(Math.random()*11) 
function sendAJAX(q1)
{
var xmlhttp;
if (window.XMLHttpRequest)
  {// code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else
  {// code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
         alert('posted value' + xmlhttp.responseText);
    }
  }
xmlhttp.open("GET","http://yourdomain.com/?q=" + q1 ,true);
xmlhttp.send();
}
</SCRIPT>

And in PHP code

<?php 
$ff = $_GET['q'];
echo $ff;
?>

edited Jun 5, 2015 at 11:19

answered Jan 12, 2014 at 7:19

Girish

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6 Comments

user3180745 Over a year ago

Can yo suggest how to achieve this for my example with a code

user3180745 Over a year ago

Thanks , I m just trying this. BTW i am running on a localhost(localhost/php2js) , How do i modify this xmlhttp.open("GET","yourdomain.com/?q" + q1 ,true);

user3180745 Over a year ago

@Girish_Jangid Is there something i am missing from the expected result, Please correct me if i am wrong jsfiddle.net/Va8d4

Girish Over a year ago

this couldn't implement in JSFIDDLE, please don't bear up and read more about AJAX working

Dimple Over a year ago

Its not working.. I am getting error undefined q in php

|

manta · Accepted Answer · 2014-01-12 07:36:55Z

1

The HTML file:

<script src='http://code.jquery.com/jquery-1.10.2.min.js'></script>
<script>
var q1=Math.floor(Math.random()*11);
$(document).ready(function(){
    $.ajax({url:"ajax.php",data: {"q1":q1}}).done(function(data){console.log(data)});
});
</script>

The PHP file: ajax.php

<?php
$ff = filter_input(INPUT_GET, 'q1', FILTER_VALIDATE_INT);
echo $ff;
?>

References:

jquery

PHP

answered Jan 12, 2014 at 7:36

manta

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5 Comments

user3180745 Over a year ago

Is there something i am missing to achieve the expected result I am nt able to pass the variable. Please find the attached files dropbox.com/sh/9gfrgo1j8ojs95f/HvbMrnFxFT

manta Over a year ago

from the looks of this, you dont need PHP at all. You could achieve this with java script. Your server will not read the php code inside a HTML file. Did you just want to write out the value of q1 inside the body tag in your HTML file?

user3180745 Over a year ago

I actually want the value of q1 from JS to store in database. Am i doing it correct, send JS variable to PHP and from PHP to mysql?

manta Over a year ago

Yes, is this just a concept? If all you wanted to store in a db was a random number, PHP could do this without JS using the rand() function.

user3180745 Over a year ago

This is just a concept, all i am looking is to find the connectivity to pass my variable from JS to store in SQL

samuel · Accepted Answer · 2016-07-07 09:43:12Z

1

you can use like this.

<html> 
    <head>
      <script type="text/javascript">
          var q1="hello"; 

          <?php 
             $ff ="<script>document.write(q1)</script>";             
          ?>
       </script>
   </head>
<body>
<?php echo $ff; ?>
 </body> 
</html>

edited Jul 7, 2016 at 9:43

samuel

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answered May 9, 2014 at 11:39

Chetan Ghadiya

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1 Comment

temo Over a year ago

This would result in $ff being string "<script>document.write(q1)</script>", but if you echo it on the page script will execute and you will see "Hello" on the page. But if you insert $ff to DB "<script>document.write(q1)</script>" will be inserted instead of "hello"

samuel · Accepted Answer · 2016-07-07 08:26:27Z

0

you can use like this.

<html> 
    <head>
      <script type="text/javascript">
          var q1="hello"; 

          <?php 
             $ff ="<script>document.write(q1)</script>";             
          ?>
       </script>
   </head>
<body>
<?php echo $ff; ?>
 </body> 
</html>

edited Jul 7, 2016 at 8:26

answered Jul 7, 2016 at 8:18

samuel

631 silver badge7 bronze badges

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