I cannot find a solution to my question, I read the hints of server-side and client-side issues already.

1. I have a js script that loads the values of a js array which is stored in localStorage, here is the code:

    <script>
    var myList = JSON.parse(localStorage.getItem('myList', '[]'));
    console.log(myList);
    </script>
   

2. I get the content of the myList array values stored locally. The values of this array are separated by a comma (,) like this:

    myList ['apple1', 'apple2', 'apple3']
   

3. I try to use this js array in php.

    <?php
    $test0 = "<script>document.writeln(myList);</script>";
   

4. I echo the $test0, it works, I get the apple1,apple2,apple3 values:

    echo $test0;
    //apple1,apple2,apple3
   

5. I change $test0 to a string (anyway it should be a string originally) and then I check whether it´s really a string, it works, it´s a string:

    $test1 = strval($test0);
    echo is.string($test1);
    // 1
   

6. I explode the string $test1 into the $test2 array and then check whether $test2 is an array, it works, $test2 is an array;

    $test2 = explode(',',$test1,0);
    echo is_array($test2);
    // 1
   

7. I echo the $test2 array values, it works, I get the values:

    foreach($test2 as $value){
    echo $value;
    }
    ?>  
    //apple1,apple2,apple3
   

8. But, if I try to use the substr() function to this $value in order to return specific characters of each value of the $value array, I get the substracted string of the $test0 variable (ript>document.writeln(myList);):

    foreach($test2 as $value){
    echo substr($value,3);
    }
    // ript>document.writeln(myList);
   

Why does not work the substr() function in this case?

Thank you for your help!