Question

I want to click on a button, a div appears, when clicking the same button it should disappear.

Actually only appearing works, how to hide it again?

Skript:

$('#button').click(function() {
  $('#ui-block-a').removeClass('visuallyhidden').addClass('ui-block-a'), function(){
  $('#ui-block-a').addClass('visuallyhidden').removeClass('ui-block-a');
  };
}); 

HTML:

 <div class="visuallyhidden" id="ui-block-a">
     <ul data-role="listview" data-filter="true" id="nav"></ul> 
 </div>

Here is try to use a callback, but it is not working…

Answer 1

If the classes are correctly set from the beginning, you can use .toggleClass() ^[docs]:

$('#ui-block-a').toggleClass('visuallyhidden ui-block-a');

Otherwise, if you explicitly want to add/remove classes, you can use .toggle():

$('#button').toggle(function() {
    $('#ui-block-a').removeClass('visuallyhidden').addClass('ui-block-a');

}, function(){
    $('#ui-block-a').addClass('visuallyhidden').removeClass('ui-block-a');
});

---

Why your code does not work:

You are not setting up a callback. You are executing two statements via the comma operator. The first part ($('#ui-block-a').addClass('...').removeClass('...')) will be executed as expected. The second part (function() {...}) will be evaluated as function expression and the result, a function, will be returned as overall result of the statement. But you are not assigning the result to anything, so it is just silently ignored.

E.g. if you’d do

// form is like `var foo = x, y;`
var foo = $('#ui-block-a').removeClass('...').addClass('...'), function(){
    $('#ui-block-a').addClass('...').removeClass(...');
};

then foo would refer to the function

function() { 
    $('#ui-block-a').addClass('...').removeClass('...');
}

But that is not what you want anyway. So putting a function there is legal, but has not special meaning and thus no effect.