Passing JS variable to PHP

Question

I am trying to pass a JS variable to PHP and have PHP echo the JS variable back. I keep getting an empty null string. What am I doing wrong?

function(u){

            if(u){
                var dt = {'ud':u};
                console.log(dt);

                $.post('xrege.php', dt, function(r){
                    console.log(r.responseText);
                    console.log(typeof(r.responseText));
                });
            }
        });


<?php

$ud = $_POST['ud'];
echo json_encode($ud);
?>

1) u is a boolean in this case. 2) You're trying to asign u to nothing. The correct syntax would be {ud: u} without the quotes. Quote from the jQuery api: $.post( "test.php", { name: "John", time: "2pm" } ); 3) Don't mix Javascript with jQuery. It should be console.log(r); — icecub
– icecub, Commented Nov 13, 2016 at 3:14
u is a variable that should have a value, I just want to check if indeed it does have a value before passing it to the server. I spent two hours scratching my head and overlooked the syntax error though, thank you. — Jay
– Jay, Commented Nov 13, 2016 at 12:06

Liang · Accepted Answer · 2016-11-13 03:36:38Z

1

you should separate php code into a different file and it should be working.

if(u){
    var dt = {'ud':u};
    console.log(dt);

    $.post('xrege.php', dt, function(r){
        console.log(r);
        console.log(typeof r);
    },"json");
}

name the above code like 123.html and keep the below code in xrege.php

<?php
$ud = $_POST['ud'];
echo json_encode($ud);
?>

answered Nov 13, 2016 at 3:36

Liang

5152 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jay Over a year ago

The code is already segregated. I am using two other PHP files that work perfectly well. But for the life of me, I cannot even get the most basic response from this one.

Collectives™ on Stack Overflow

Passing JS variable to PHP

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related