[php] Send JavaScript variable to PHP variable

First I thought that I had to convert JavaScript to PHP, but then I found out that I cannot because of server and client side executions. So now I simply want to send ONE variable

<script type="text/javascript">
function scriptvariable()
{        
    var theContents = "the variable";
}
</script>

to a PHP variable

<?php
$phpvariable
?>

That function in the JavaScript executes when let's say I click on a button.

Now I have no idea on how to assign that phpvariable to the JavaScript one to use the phpvariable to look up stuff in my database. I know I can add it to my url or some thing and refresh the page, but I would like to do it with AJAX as I might have to use this Ajax method further in my webpage.

So is there an easy way to do this without having to dump pages of code on my page to do one simple thing?

This question is related to php javascript ajax variables

The answer is


As Jordan already said you have to post back the javascript variable to your server before the server can handle the value. To do this you can either program a javascript function that submits a form - or you can use ajax / jquery. jQuery.post

Maybe the most easiest approach for you is something like this

function myJavascriptFunction() { 
  var javascriptVariable = "John";
  window.location.href = "myphpfile.php?name=" + javascriptVariable; 
}

On your myphpfile.php you can use $_GET['name'] after your javascript was executed.

Regards


It depends on the way your page behaves. If you want this to happens asynchronously, you have to use AJAX. Try out "jQuery post()" on Google to find some tuts.

In other case, if this will happen when a user submits a form, you can send the variable in an hidden field or append ?variableName=someValue" to then end of the URL you are opening. :

http://www.somesite.com/send.php?variableName=someValue

or

http://www.somesite.com/send.php?variableName=someValue&anotherVariable=anotherValue

This way, from PHP you can access this value as:

$phpVariableName = $_POST["variableName"];

for forms using POST method or:

$phpVariableName = $_GET["variableName"];

for forms using GET method or the append to url method I've mentioned above (querystring).


PHP runs on the server and Javascript runs on the client, so you can't set a PHP variable to equal a Javascript variable without sending the value to the server. You can, however, set a Javascript variable to equal a PHP variable:

<script type="text/javascript">
  var foo = '<?php echo $foo ?>';
</script>

To send a Javascript value to PHP you'd need to use AJAX. With jQuery, it would look something like this (most basic example possible):

var variableToSend = 'foo';
$.post('file.php', {variable: variableToSend});

On your server, you would need to receive the variable sent in the post:

$variable = $_POST['variable'];

Examples related to php

I am receiving warning in Facebook Application using PHP SDK Pass PDO prepared statement to variables Parse error: syntax error, unexpected [ Preg_match backtrack error Removing "http://" from a string How do I hide the PHP explode delimiter from submitted form results? Problems with installation of Google App Engine SDK for php in OS X Laravel 4 with Sentry 2 add user to a group on Registration php & mysql query not echoing in html with tags? How do I show a message in the foreach loop?

Examples related to javascript

need to add a class to an element How to make a variable accessible outside a function? Hide Signs that Meteor.js was Used How to create a showdown.js markdown extension Please help me convert this script to a simple image slider Highlight Anchor Links when user manually scrolls? Summing radio input values How to execute an action before close metro app WinJS javascript, for loop defines a dynamic variable name Getting all files in directory with ajax

Examples related to ajax

Getting all files in directory with ajax Cross-Origin Read Blocking (CORB) Jquery AJAX: No 'Access-Control-Allow-Origin' header is present on the requested resource Fetch API request timeout? How do I post form data with fetch api? Ajax LARAVEL 419 POST error Laravel 5.5 ajax call 419 (unknown status) How to allow CORS in react.js? Angular 2: How to access an HTTP response body? How to post a file from a form with Axios

Examples related to variables

When to create variables (memory management) How to print a Groovy variable in Jenkins? What does ${} (dollar sign and curly braces) mean in a string in Javascript? How to access global variables How to initialize a variable of date type in java? How to define a variable in a Dockerfile? Why does foo = filter(...) return a <filter object>, not a list? How can I pass variable to ansible playbook in the command line? How do I use this JavaScript variable in HTML? Static vs class functions/variables in Swift classes?