jQuery: check if a div contains a div with class on

Question

I have several <div> elements inside another <div>.

I want to do an if statement which is true if a div inside the top div contains class on.

HTML:

<div class="toDiv">
    <div>

    </div>
    <div class="on">

    </div>
</div>

jQuery:

if ($(".toDiv").contains("on")) {
    // do something
}

Answer 1

$('div.toDiv').each(function() {
    if($('div.on', this).length > 0) {
        //do something with this
    }
});

Answer 2

if ($(".toDiv").find(".on").length > 0){ 
  ///do something
}

or

if ($(".toDiv .on").length > 0){ 
  ///do something
}