How to assign javascript variable to php variable? Other than Cookies🙂

Answer 1

The Javascript variables can be posted to the PHP page using HTTP POST or HTTP GET.

Then, the PHP code can extract the values using code like below:

#Querystring value
$age = $_GET["age"];

or

#Web Form Post value
$age = $_POST["age"];

or

#Either Post or Get values
$age = $_REQUEST["age"];

Answer 2

Kode Krasher It sounds like you had fun getting this figured out on your computer before hitting that brick wall with running it in SL.

I already knew it wasn't going to work on SL, so I didn't bother trying to demo it the post back scenario. 😉

That said, a few days ago, I originally misread this question and thought the OP was asking about how to initialize JS variables from PHP variables.

So... at first, I wrote the following code to demonstrate:

https://code.sololearn.com/wV6m8X2M1tXD/?ref=app

After realizing this question was about setting PHP variables from the client, I decided to simply explain the 3 different Super Globals objects that can be used to extract values other than using $_COOKIES.

I'm sharing this code with you now since I think you might be able to connect the dots on how it can be further extended to include the PHP code to handle the post back scenario with hidden inputs. 😉

Hopefully, this code is somewhat helpful. But I think you already get it. 👌

Answer 3

Many had asked this question, and many had tried to answer with different approaches. But I'm still thinking it's not possible because Javascript runs on front-end, while PHP runs on back-end. How can they exchange memory when they run on different engine?

Answer 4

As Kode Krasher and David Carroll suggested, you can POST the data (JS variable value) to the backend (PHP script) asynchronously.

Something like this:

JS:
const jsVar = 2021;

function setPhpVar() {
fetch(location.href, {
method: 'POST',
body: {jsVar},
});
}

PHP:
$phpVar = $_POST['jsVar'] ?? 1970;

https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch

Answer 5

Kode Krasher Asynchronous HTTP requests have been possible with JavaScript for over 20 years. It is not really new technology.

Answer 6

Kode Krasher I get it 👌