This overview is handy towards stepping back and forth between jQuery and JavaScript. First line is jQuery and the following line is the corresponding function in JavaScript.
jQuery
$(document).ready(function() { // code… });
JavaScript
document.addEventListener("DOMContentLoaded", function() { // code… });
jQuery
var divs = $("div");
JavaScript
var divs = document.querySelectorAll("div");
jQuery
var newDiv = $("<div/>");
JavaScript
var newDiv = document.createElement("div");
jQuery
newDiv.addClass("foo");
JavaScript
newDiv.classList.add("foo");
jQuery
newDiv.toggleClass("foo");
JavaScript
newDiv.classList.toggle("foo");
jQuery
$("a").click(function() { // code… })
JavaScript
[].forEach.call(document.querySelectorAll("a"), function(el) { el.addEventListener("click", function() { // code… }); });
jQuery
$("body").append($("<p/>"));
JavaScript
document.body.appendChild(document.createElement("p"));
jQuery
$("img").filter(":first").attr("alt", "My image");
JavaScript
document.querySelector("img").setAttribute("alt", "My image");
jQuery
var parent = $("#about").parent();
JavaScript
var parent = document.getElementById("about").parentNode;
jQuery
var clonedElement = $("#about").clone();
JavaScript
var clonedElement = document.getElementById("about").cloneNode(true);
jQuery
$("#wrap").empty();
JavaScript
var wrap = document.getElementById("wrap"); while(wrap.firstChild) wrap.removeChild(wrap.firstChild);
jQuery
if($("#wrap").is(":empty"))
JavaScript
if(!document.getElementById("wrap").hasChildNodes())
jQuery
var nextElement = $("#wrap").next();
JavaScript
var nextElement = document.getElementById("wrap").nextSibling;