脚本问题 - 隐藏/显示元素

Question

I'm working on a website, and i have a part which consist in hide/show elements when the user's clicking on a menu.

Here is the issue :

$('[id^="answer"]').hide();

$('[class^="test"]').on('click', function(e){

    e.preventDefault();

    var numb = this.className.replace('test', '');

        $('[id^="answer"]').hide();
        $('#answer' + numb).show();



});


$(document).ready(function(){
  $('a').click(function(){
    $('a').removeClass("active");
    $(this).addClass("active");

});
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<a class="test3" href="#">> test</a>

<div id="answer3">
                <div class="center">
                        <p>hello</p>
                </div>
</div>

</div>

Answer 1

I tried it in JSBin and could not reproduce the error:

<a class="test2" href="#">Test 2</a>
<a class="test3" href="#">Test 3</a>

<div id="answer2">
  Answer2
</div>

<div id="answer3">
  Answer3
</div>

<script>
  $('[id^="answer"]').hide();

  $('[class^="test"]').on('click', function(e){

    e.preventDefault();

    var numb = this.className.replace('test', '');

        $('[id^="answer"]').hide();
        $('#answer' + numb).show();

  });
</script>

https://jsbin.com/kekidusogo/edit?html,console,output