Question

I have some Condition at PHP and if it’s true i need php variable to get javascript function:
Something like that:

<?php
if(x == true){
$x = <script type="text/javascript">xfunction();</script>;
}
?>

I don’t really know how to get them to combination.

Answer 1

To invoke a function onload when rendering your document.. you can just echo out a self executing function.

<?php 
 // your other code
 if( $x ) { // no need to check if true... this will fail if falsey 
   echo "<script>";
   echo "(function() { xfunction(); }());"; // I will execute when the parser hits me
   echo "</script>";
 }
 // or (after reading your comments above) 
 if( $x ) { 
   $x  = "";
   $x .= "<script>";
   $x .= "(function() { xfunction(); }());"; // I will execute when the parser hits me
   $x .= "</script>";
 }
 // somewhere else in the document.... 
 echo $x;

or if you are trying to pass values from javascript to php you will need to make use of HTTP Request variables (POST, GET) or XHR…

Example of the XHR:

var request = new XMLHttpRequest();  
request.open('POST', 'http://www.somepage.com/foo.php', true);  
request.send('data=somedata');  

if (request.status === "200") {  
  console.log(request.responseText);  
}  

and on the php end of like access it with $_POST['data']

More reading can be done about PHP Request variables here

More information regarding XHR can be read here