Question

<div id="first">
    <div id="here">...</div>
</div>
<div id="second">
    <div id="here">...</div>
</div>

jquery:

$("#second #here").click(function(){});

how to write jquery to detect when I click the second ?

Answer 1

This is the wrong question to be asking, because you are not supposed to have duplicate IDs in a document. An ID is like the social security number of an element. You can’t give multiple elements the same one, because then when you tell Javascript to find an element by ID it will be terribly confused by the fact there’s more than one and give you unexpected results. The reason ID lookups are as fast as they are is because the browser can have a hash table of ID->element – violating that understanding is a bad practice, to say the least.

When you have several elements that are all of the same “type”, the proper practice is to class them:

<div id="first">
    <div class="here">...</div>
</div>
<div id="second">
    <div class="here">...</div>
</div>

So then you can do:

$('#first').find('div.here');

Or:

$('div.here', '#second');

Or:

$('#first div.here');

Which would all return what you expect them to return.