Javascript in a php variable

//this is my code 

$value = <<<data
       <!--instead of writing data we can name it anything 
       as long as we close it with the same name, 
       and that name must not be a keyword in javascript -->

        <script>
         document.write("hello world");
        </script>
       data;

so the php variable $value will not store the string "hello world" inside it,
so the php variable is just a temporary container for the javascript code and nothing else,
and if we echo the vairable like this:-
  
echo $value;
then hello world will be printed in the browser page,
and it is the same as using echo to excute a javascript code, so it is as:-
  
echo "<script>document.write(\"hello world\")</script>"
  
  
  
//using console instead of document.write
  
$value = <<<inConsole
        <script>
         console.log("hello world");
        </script>
       inConsole;


but the value will not be printed in the console unless we echo the variable, 
like this:-

echo $value
then hello world will be printed in the console
  
  
  
//other examples such as storing data to localstorage
  
$local = <<<localstorage
        <script>
         localStorage.setItem("anything", "hello");
        </script>
        localstorage;


but this code will not work until we echo the variable such as:-
echo $local

and if we open the console and write localstorage then the item anything
with its value hello will appear
  
  
  
  
  
  
and if we want to remove the item from localstorage then use this code:-

$local = <<<localstorage
        <script>
         localStorage.removeItem("anything");
        </script>
        localstorage;

        echo $local;

note: never forget to use the echo statement or the code will not work
  
  
  
  
and if we want to get data from localstorage, we use this code

$local = <<<localstorage
        <script>
         let a = localStorage.getItem("anything");
         document.write(a);
        </script>
        localstorage;

        echo $local;

then the value of the varaible a will be print in the webpage,

Source: stackoverflow.com

Similar codes

0 vote166 views1 answer
Php creating a subdomain automatically in cpanel
PHP
6 votes234 views3 answers
Laravel route namespace
PHP
-1 vote234 views2 answers
Toast in php
PHP
5 votes170 views2 answers
How to clear session in laravel
PHP
7 votes148 views1 answer
Php artisan passport install command
PHP
0 vote158 views1 answer
Wpml language switcher shortcode
PHP
1 vote153 views1 answer
Teruglopende for loop php
PHP
1 vote139 views1 answer
Find substring regx php
PHP
0 vote151 views1 answer
Add custom attribute for validation errors laravel
PHP
0 vote254 views3 answers
When you click on the search button, it is moved to the page laravel
PHP