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What are the 8 types of javascript events?

Ngày đăng: 08/09/2022
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HTML events are "things" that happen to HTML elements.

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When JavaScript is used in HTML pages, JavaScript can "react" on these events.

HTML Events

An HTML event can be something the browser does, or something a user does.

Here are some examples of HTML events:

  • An HTML web page has finished loading
  • An HTML input field was changed
  • An HTML button was clicked

Often, when events happen, you may want to do something.

JavaScript lets you execute code when events are detected.

HTML allows event handler attributes, with JavaScript code, to be added to HTML elements.

With single quotes:

'some JavaScript'>

With double quotes:

"some JavaScript">

In the following example, an onclick attribute (with code), is added to a

Try it Yourself »

In the example above, the JavaScript code changes the content of the element with id="demo".

In the next example, the code changes the content of its own element (using this.innerHTML):

Example


Try it Yourself »

JavaScript code is often several lines long. It is more common to see event attributes calling functions:

Common HTML Events

Here is a list of some common HTML events:

EventDescription
onchange An HTML element has been changed
onclick The user clicks an HTML element
onmouseover The user moves the mouse over an HTML element
onmouseout The user moves the mouse away from an HTML element
onkeydown The user pushes a keyboard key
onload The browser has finished loading the page

The list is much longer: W3Schools JavaScript Reference HTML DOM Events.

JavaScript Event Handlers

Event handlers can be used to handle and verify user input, user actions, and browser actions:

  • Things that should be done every time a page loads
  • Things that should be done when the page is closed
  • Action that should be performed when a user clicks a button
  • Content that should be verified when a user inputs data
  • And more ...

Many different methods can be used to let JavaScript work with events:

  • HTML event attributes can execute JavaScript code directly
  • HTML event attributes can call JavaScript functions
  • You can assign your own event handler functions to HTML elements
  • You can prevent events from being sent or being handled
  • And more ...

You will learn a lot more about events and event handlers in the HTML DOM chapters.

Test Yourself With Exercises

Exercise:

The

Start the Exercise


Event typeDescriptionDocumentation
Animation

Events related to the Web Animation API.

Used to respond to changes in animation status (e.g. when an animation starts or ends).

Animation events fired on Document, Window, HTMLElement.
Asynchronous data fetching

Events related to the fetching data.

 Events fired on AbortSignal, XMLHttpRequest, FileReader.
Clipboard

Events related to the Clipboard API.

Used to notify when content is cut, copied, or pasted.

 Events fired on Document, Element, Window.
Composition

Events related to composition; entering text "indirectly" (rather than using normal keyboard presses).

For example, text entered via a speech to text engine, or using special key combinations that modify keyboard presses to represent new characters in another language.

Events fired on Element.
CSS transition

Events related to CSS Transitions.

Provides notification events when CSS transitions start, stop, are cancelled, etc.

Events fired on Document, HTMLElement, Window.
Database

Events related to database operations: opening, closing, transactions, errors, etc.

Events fired on IDBDatabase, IDBOpenDBRequest, IDBRequest, IDBTransaction.
DOM mutation

Events related to modifications to the Document Object Model (DOM) hierarchy and nodes.

Warning: Mutation Events are deprecated. Mutation Observers should be used instead.

Drag'n'drop, Wheel

Events related to using the HTML Drag and Drop API and wheel events.

Drag and Wheel events are derived from mouse events. While they are fired when using mouse wheel or drag/drop, they may also be used with other appropriate hardware.

Drag events fired on Document

Wheel events fired on Document and Element

Focus

Events related to elements gaining and losing focus.

 Events fired on Element, Window.
Form

Events related to forms being constructed, reset and submitted.

 Events fired on HTMLFormElement.
Fullscreen

Events related to the Fullscreen API.

Used to notify when the transitioning between full screen and windowed modes, and also of errors occurring during this transition.

Events fired on Document, Element.
Gamepad

Events related to the Gamepad API.

Events fired on Window.
Gestures

Touch events are recommended for implementing gestures.

Events fired on Document, Element.

In addition there are a number of non-standard gesture events:

  • Non-standard WebKit specific events on Element: gesturestart event, gesturechange event, gestureend event.
  • Non-standard IE specific events on Element: MSGestureStart, MSGestureChange, MSGestureEnd, MSGestureHold, MSGestureTap.
  • Mouse gesture events for Firefox Addons
History

Events related to the History API.

Events fired on Window.
HTML element content display management

Events related to changing the state of a display or textual element.

 Events fired on HTMLDetailsElement, HTMLDialogElement, HTMLSlotElement.
Inputs

Events related to HTML input elements e.g. ,