select multiple elements declared as variable

in the example below how to say a and instead of $('.lorem, .ipsum').show();

var a = $('.lorem');
var b = $('.ipsum');
 $('.lorem, .ipsum').show();
//a and;
.lorem, .ipsum{display:none;}
<script src=""></script>
<div class='lorem'>lorem</div>
<div class='ipsum'>ipsum</div>


You can use .add():


The .add() method allows a selector string, or a jQuery object, one or more element node references, or an HTML string to be added to an existing jQuery object. Note that a new jQuery object is returned; the original a in the above example is unchanged.