can't convert string to int from value was getting by javascript code

Question

in my case I want to convert a string value to integer , the value was returned by a JavaScript code, but when i convert in i got, a type int(0) so the values wasn't converted correctly

can anyone help me please, thanks in advance

this is the code

$screenwidth = "<script>document.write(screen.width);</script>";
var_dump($screenwidth);
var_dump((int)$screenwidth);

this what i get as output



string(46)"1200"

int(0)

html script code won't run in php, so what happens is it tries to convert your html string into an integer. — Patrick Evans, Dec 19 '20 at 01:13
See: [Getting the screen resolution using PHP](https://stackoverflow.com/a/1504526) — Nick Parsons, Dec 19 '20 at 01:16
There is no `1200` display. https://3v4l.org/ZlYGX please display actual results, or nothing. — user3783243, Dec 19 '20 at 02:59

score 0 · Answer 1 · answered Dec 19 '20 at 01:21

PHP code is executed on the server, Javascript is sent from the server to the client, where it is then executed. You either want to:

echo the script to the page (PHP will not have access to screen width) echo "<script>document.write(screen.width);</script>";
make an ajax request to the server with the variable so that PHP can process it (PHP will be in a different context to when page was created) <script>fetch(URL + "/index.php?width=" + screen.width);</script>

can't convert string to int from value was getting by javascript code

1 Answers1