Question

I can’t get the string from the JS code to the PHP code

here is the code, which initializes when I push enter in a text input:

$('#user').keypress(function(e) {
    if(e.which == 13) {

  var val = $(this).val();

$.ajax({
    type: 'POST',
    url: 'index.php',
    data: ({'latt':val
            })
        });


<?php

$val = $_POST['latt'];

echo "alert('$val')";

?>

    }
});

where #user is the id of this text input

When I run the code, I see the alert that shows nothing

Before I exactly know that the JS val is not empty

Thank you in advance

P.S. my page is index.php

Answer 1

PHP code runs before the page is sent to the browser. That PHP block will simply echo the value of $_POST['latt'] as it stood when you navigated to the page. You need to access the response from the server in the success callback:

$('#user').keypress(function(e) {
    if (e.which == 13) {

        var val = $(this).val();

        $.ajax({
            type: 'POST',
            url: 'index.php',
            data: {
                'latt': val
            },
            success: function(data) {
                alert(data.responseText);
            }

        });
    }
});