如何将php变量传递给javascript？

Question

I am using following code to pass PHP variables to javascript. but it is not working.

 function gto(str) {
   document.getElementById('goto').action = str;
   document.getElementById('ID').value = <?php echo "$userid" ?>;
   document.getElementById('name').value = <?php echo "$user_name" ?>;
   document.getElementById('gname').value = <?php echo "$usergname" ?>;
   document.getElementById('fmname').value = <?php echo "$userfname" ?>;
   document.getElementById('img').value = <?php echo "$userimg" ?>;
   document.getElementById('email').value = <?php echo "$useremail" ?>;
   document.getElementById('goto').submit();
  }

Following is the PHP code

<?php
    if($_POST["name"] == null)
    {
        $user_name = 'Annomyous';   
    }
    else{
        $user_name = $_POST["name"];
        $userid=  $_POST["id"];
        $usergname=  $_POST["gname"];
        $userfname=  $_POST["fname"];
        $userimg=  $_POST["img"];
        $useremail=  $_POST["email"];
    }
    echo "<p style='color : white'>$user_name";
    echo "$userid" ;
    echo "$gname";
    echo "$fname";
    echo "$img";
    echo "$email";
    echo "$user_name";
    echo "$user_name</p>";
    $user_name =htmlspecialchars($user_name);
    $user_name =str_replace("<script>","", $user_name);
    ?>


the output is a follows:
ReAlItY TuTs104598758504708047866ReAlItY TuTsReAlItY TuTs//this is php echo output.

JAVASCRIPT OUTPUT:-

 function gto(str) {
       document .getElementById('goto').action = str;
       document.getElementById('ID').value = ;
       document.getElementById('name').value = Annomyous;
       document.getElementById('gname').value = ;
       document.getElementById('fmname').value = ;
       document.getElementById('img').value = ;
       document.getElementById('email').value = ;
       document.getElementById('goto').submit();
   }

Function gto is called here:

<button class="w3-btn header-btn" onclick="gto('Contact.php');">Contact Us</button>

I can see in PHP output I am getting all variable output. but nin juavascript im getting only Annonymous why???? I need to pass post variables to contact us so i am using the form tag and javascript but this is not working Please help me! Thanks in Advance

Answer 1

values from php to js can be passed in many ways, here's one of them
try to pass the php values when calling the js function, like this:-

<button onclick="gto('Contact.php','<?php echo $userid;?>','<?php echo $username;?>');">Contact Us</button>

and then get values on js function like this:-

 function gto(str,userid,username) {

   document .getElementById('goto').action = str;
   document.getElementById('ID').value = userid;
   document.getElementById('name').value =username;

 }

that's it, now use the values in js as your wish

Answer 2

Uh, found another issue. The js is in smart quotes, which won't work... "`" is invalid. use "'". Also, w3schools can't handle php in their editor, so it's no use. Example for POST requests: https://www.w3schools.com/code/tryit.asp?filename=FQSA8MJYGJ47

Hope this helps.