jquery visibility depending on existence of other div

(use display:none)

by Roberto Apasajja

HTML

<div id="one">
    one
    <div id="two">
        two
    </div>
</div>

<div id="first">
    first
    <div id="second">
        second
    </div>
    <div id="secondb">
        secondb
    </div>
</div>

CSS

#one{
    width:200px;height:100px;
    background:pink;
}

#two{
    width:100px;height:50px;
    background:purple
}

#first{
    width:200px;height:140px;
    background:green
}

#second{
    width:100px;height:50px;
    background:red;
    display:none;
}

#secondb{
    width:100px;height:50px;
    background:yellow;
    display:none;
}

JavaScript

if($('#two').length > 0) {
    $('#second').show()
}

if($('#two').length == 0) {
    $('#secondb').show()
}