如何使用 cookie 将 javascript 变量传递给 php 变量

Question

when I'm trying to run this code to forward javascript value (cookie_user) to PHP value (username).

here is my code:

 <script> // Creating a cookie after the document is ready $(document).ready(function () { var cookies = document.cookie.split(";") var cookiePair = cookies[0].split("="); var cookie_user=cookiePair[1]); createCookie("username", cookie_user, "10"); }); // Function to create the cookie function createCookie(name, value, days) { var expires; if (days) { var date = new Date(); date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000)); expires = "; expires=" + date.toGMTString(); } else { expires = ""; } document.cookie = escape(name) + "=" + escape(value) + expires + "; path=/"; } </script> <?php $username= $_COOKIE["username"]; ?>

when I execute the code, I get this error: "Undefined index: username" the PHP part is not working. what should I do to make it right?

Thanks

Answer 1

You have an issue in your existing JS code with extra parenthesis on line 5 , Also you can't access cookie instantly from PHP after setting it on javascript .

So you've to modify on your PHP part also, initially check cookie exists or not with isset() ? when you reload your page it will set the username cookie that will be accessible on your $_COOKIE['username'] later.

ON JS ,

$(document).ready(function () { 

    var cookies = document.cookie.split(";")
    var cookiePair = cookies[0].split("=");
    var cookie_user=cookiePair[1]; // remove ending parenthesis here  
    createCookie("username", cookie_user, "10"); 
}); 

// Function to create the cookie 
function createCookie(name, value, days) { 
    var expires; 

    if (days) { 
        var date = new Date(); 
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000)); 
        expires = "; expires=" + date.toGMTString(); 
    } 

    else { 
        expires = ""; 
    } 

    document.cookie = escape(name) + "=" +  
    escape(value) + expires + "; path=/"; 
} 

ON PHP ,

<?php
$username = isset($_COOKIE['username'])? $_COOKIE['username']:'cookie not set';
echo $username;
?>

Alternatively, you can use ajax to send data from your client-side js to server-side PHP