jQuery $ .post（）使用输出数据作为选择器

Question

I am trying to build a quiz environment. The user selects an answer and then clicks submit. Upon submit, the following jquery is called:

$(document).ready(function() {
    $('.btn-large').click(function() {
        $.post("correct_quiz.php",
        {
            choices : $('input[name=choice][type=radio]:checked').serialize()
        },
        function(data) {
            var temp = '#correct' + data;
            var temp2 = '#correct3';
            $(temp).show();  // Make the wrong/right icons visible
        });
    });
});

This jquery makes a green or red icon appear, based on whether the answer was correct or not. The correct_quiz.php script contains:

<?php 
       $root = "/users/stadius/maapc/public_html/";
       include($root . "connect_to_database.php");

       $choices = $_POST['choices']; // This will for example output "choice=3"
       echo substr($choices,7,7); // This will then output "3"
?>

I ran into a problem, when I try the above jquery code with variable temp2 the script works like I want. But when I try it with variable temp it doesn't. When I debug, I see that they contain exactly the same string though: both are '#correct3' (when I choose the 3rd answer).

So why is this not working when I use variable temp, and is working when using temp2?

Answer 1

I think your problem is in this line:

echo substr($choices,7,7);

Try to use:

$list = explode('=', $choices);

echo $list[1];

instead of substr