Hide div by default and show it on click with bootstrap

I want to show and hide a div, but I want it to be hidden by default and to be able to show and hide it on click. Here is the code that I have made :

<a class="button" onclick="$('#target').toggle();">
 <i class="fa fa-level-down"></i>
</a>

<div id="target"> 
 Hello world... 
</div>

Here I propose a way to do this exclusively using the Bootstrap framework built-in functionality.

1. You need to make sure the target div has an ID.
2. Bootstrap has a class "collapse", this will hide your block by default. If you want your div to be collapsible AND be shown by default you need to add "in" class to the collapse. Otherwise the toggle behavior will not work properly.
3. Then, on your hyperlink (also works for buttons), add an href attribute that points to your target div.
4. Finally, add the attribute data-toggle="collapse" to instruct Bootstrap to add an appropriate toggle script to this tag.

Here is a code sample than can be copy-pasted directly on a page that already includes Bootstrap framework (up to version 3.4.1):

<a href="#Foo" class="btn btn-default" data-toggle="collapse">Toggle Foo</a>
<button href="#Bar" class="btn btn-default" data-toggle="collapse">Toggle Bar</button>
<div id="Foo" class="collapse">
    This div (Foo) is hidden by default
</div>
<div id="Bar" class="collapse in">
    This div (Bar) is shown by default and can toggle
</div>

Just add water style="display:none"; to the <div>

Fiddles I say: http://jsfiddle.net/krY56/13/

jQuery:

function toggler(divId) {
    $("#" + divId).toggle();
}

Preferred to have a CSS Class .hidden

.hidden {
     display:none;
}

Try this one:

<button class="button" onclick="$('#target').toggle();">
    Show/Hide
</button>
<div id="target" style="display: none">
    Hide show.....
</div>

I realize this question is a bit dated and since it shows up on Google search for similar issue I thought I will expand a little bit more on top of @CowWarrior's answer. I was looking for somewhat similar solution, and after scouring through countless SO question/answers and Bootstrap documentations the solution was pretty simple. Again, this would be using inbuilt Bootstrap collapse class to show/hide divs and Bootstrap's "Collapse Event".

What I realized is that it is easy to do it using a Bootstrap Accordion, but most of the time even though the functionality required is "somewhat" similar to an Accordion, it's different in a way that one would want to show hide <div> based on, lets say, menu buttons on a navbar. Below is a simple solution to this. The anchor tags (<a>) could be navbar items and based on a collapse event the corresponding div will replace the existing div. It looks slightly sloppy in CodeSnippet, but it is pretty close to achieving the functionality-

All that the JavaScript does is makes all the other <div> hide using

$(".main-container.collapse").not($(this)).collapse('hide');

when the loaded <div> is displayed by checking the Collapse event shown.bs.collapse. Here's the Bootstrap documentation on Collapse Event.

Note: main-container is just a custom class.

Here it goes-

$(".main-container.collapse").on('shown.bs.collapse', function () {    
//when a collapsed div is shown hide all other collapsible divs that are visible
       $(".main-container.collapse").not($(this)).collapse('hide');
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>

<a href="#Foo" class="btn btn-default" data-toggle="collapse">Toggle Foo</a>
<a href="#Bar" class="btn btn-default" data-toggle="collapse">Toggle Bar</a>

<div id="Bar" class="main-container collapse in">
    This div (#Bar) is shown by default and can toggle
</div>
<div id="Foo" class="main-container collapse">
    This div (#Foo) is hidden by default
</div>