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 vote285 views1 answer
Laravel Http client throw exception if request is not successful
PHP Laravel
0 vote308 views1 answer
Object of class stdclass could not be converted to string php laravel
PHP Laravel
6 votes258 views1 answer
Laravel route param blade
PHP
0 vote268 views1 answer
Php subtract seconds from datetime
PHP
0 vote273 views1 answer
Laravel imap - Set message flags
PHP
0 vote293 views1 answer
Filter child table data from parent laravel eloquent
PHP Laravel
37 votes246 views6 answers
Php hash
PHP
4 votes266 views3 answers
Laravel execute command from terminal
PHP
104 votes454 views6 answers
String length php
PHP
0 vote291 views1 answer
Jkhkjh
PHP