jQuery - MDN Web Docs Glossary: Definitions of Web-related terms 编辑

jQuery is a JavaScript Library that focuses on simplifying DOM manipulation, AJAX calls, and Event handling.

jQuery uses a format, $(selector).action() to assign an element(s) to an event. To explain it in detail, $(selector) will call jQuery to select selector element(s), and assign it to an event API called .action().

$(document).ready(function(){
  alert("Hello World!");
  $("#blackBox").hide();
});

The above code carries out the same function as the following code:

window.onload = function() {
  alert("Hello World!");
  document.getElementById("blackBox").style.display = "none";
};

Or:

window.addEventListener("load", () => {
  alert("Hello World!");
  document.getElementById("blackBox").style.display = "none";
});

Learn more

General knowledge

• jQuery on Wikipedia
• jQuery Official Website

Technical information

• Offical API reference documentation