Question

I want to select all li elements from ul having class “one” only

<ul class="one">
<li class="heading">
<li class="list">
<li class="list">
<li class="list">
<li class="list">
</ul>       
<ul class="one two ">
<li class="heading">
<li class="list">
<li class="list">
<li class="list">
<li class="list">
</ul>                        

Answer 1

Easiest:

$('ul[class="one"] li');

Alternative, select .one but not .two:

$('ul.one:not(.two) li');