show() div problem

I am an absolute beginner in this field. I have written the following code but it's not working. Can someone explain where is the error?

<script type="text/javascript">
    $("button").click(function(){
        $("div").show("slow");
    });
</script>

<button>show</button>
<div style="min-height:300px; min-width:400px; border:10px solid grey; display:no开发者_JAVA百科ne;"></div>
<a href="http://#" style="display: none">this is a link</a>

You execute the jQuery before the button is there. So at the point jQuery is executed, the button is not existent.

The solution is to use $(document).ready(...).

All elements on a page (HTML) are parsed to the DOM of that page. The DOM is a hierarchical collection of all elements. You can select elements out of it using jQuery.

However, obviously the DOM needs to be fully there before you can select the elements. In your case, you first select the button, and create it afterwards. That does not work. At the time of the selector the button does not exist yet.

Using jQuery's $(document).ready(), you can defer the function containing selectors until the DOM is fully loaded and parsed - at which time the selector works because the elements are there.

 <script type="text/javascript">
$(document).ready(function() {

        $("button").click(function(){
            $("div").show("slow");
        });

});
        </script>

        <button>show</button>
        <div style= "min-height:300px; min-width:400px; border:10px solid grey; display:none;"></div>
         <a href="http://#" style="display: none">this is a link</a>

You may be trying to listen for the click event before the button exists. Try waiting for the page contents to load:

<script type="text/javascript">
    $(document).ready(function() {
        $("button").click(function(){
            $("div").show("slow");
        });
    });
</script>

<button>show</button>
<div style= "min-height:300px; min-width:400px; border:10px solid grey; display:none;"></div>
<a href="http://#" style="display: none">this is a link</a>

As you can see from the fiddle here http://jsfiddle.net/bQUFE/ your code works (the div is shown when you click)

If you don't have this result always check:

1)that you loaded jquery before your script

2)Always use $(document).ready() like this:

$(document).ready(function(){
    $("button").click(function(){
        $("div").show("slow");
    });
}); 

the javascript is executed before the document has loaded, so the click-handler can't be attached to the button. to avoid this, wrap your code into a domready-function like this:

$(document).ready(function() {
    $("button").click(function(){
        $("div").show("slow");
    });
}

It probably is working but as your <div></div> is empty you might notice it.

Also make sure you only run your JQuery script AFTER the div has been added to your HTML.

May I also suggest to use better identifiers, because you might eventually have many div's and buttons on your page.

Example:

<button id="btn1">Click me</button>    
<div id="hidden_div" style="display: none">
    Hello there!
</div>

<script type="text/javascript">
   $('button#btn1').click(function() {
        $('div#hidden_div').show('slow');
   });
</script>

You code runs before the button is created so it cannot bind the event.

So you need to put your code in the document.ready event. In jQuery this is handled by $(document).ready(handler) or $(handler).

Documentation at http://api.jquery.com/ready/

Fix to your code to make it work

$(function(){ 
    $("button").click(function(){
        $("div").show("slow");
    });
});

demo at http://jsfiddle.net/gaby/vkrzt/

you need to give your elements "id"

so:

<button id="mybutton"></button>

and

<div id="mydiv"></div>

Then you'll use $("#mybutton") or $("#mydiv") to call these