jQuery Constructor Demo
First Paragraph, no class defined.
Second Paragraph, with a class and internal span.
Third Paragraph with an ID.
Div with span won't get highlighted.
JavaScript Source
/* Callback constructor */
jQuery(function() {
/* Selector constructors */
var paras = $("p").css("font-weight", "bold");
$(".second").css("font-size", "1.3em");
/* Using context to constrain the selector */
$("span", paras).css("background-color", "silver");
/* Constructor using an element */
var third = document.getElementById("third");
$(third).css({"border" : "1px solid black", "width":"200px"});
/* Constructor using an html snippet */
$("<p>Fourth paragraph created on the fly.</p>").appendTo("#example");
});