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Assign a Javascript variable to PHP variable

When working with PHP and JavaScript together, there are times when you need to pass values from JavaScript to PHP. This can be done by assigning a JavaScript variable to a PHP variable. In this post, We will explain different methods to do that.
<script> document.cookie = "js_var_value = " + localStorage.value </script>
    $php_var_val= $_COOKIE['js_var_value'];
    echo $php_var_val;
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Why do we assign a Javascript variable to a PHP variable? 

There are many reasons why one might want to assign a Javascript variable to a PHP variable. Some possible reasons include:

-To pass data from Javascript to PHP (for example, to use PHP to process or store data that was entered into a form via Javascript)

-To make use of PHP's built-in functions and libraries from within Javascript

-To take advantage of PHP's faster execution speed when working with large data sets or complex algorithms.

Use document.cookie and $_COOKIE to assign a JS variable to a PHP variable

The document.cookie is used to store cookies in javascript and  $_COOKIE is a PHP superglobal variable that is used to access cookies. We will use document.cookie to store javascript variable value to a cookie and access it in PHP using $_COOKIE.

    var user_name = "Rohit";
    document.cookie = "name = " + user_name;

    $name= $_COOKIE['name'];
    echo $name;

In the above code example:

  1. We have a Javascript variable named user_name that contains a string value.
  2. We are creating a cookie named name in Javascript and assigning it the user_name variable value.
  3. In the PHP code, we are getting the cookie using $_COOKIE['name'].
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