DOM: Add/Remove Event Handler

By Xah Lee. Date: . Last updated: .

This page shows you how to add/remove event handler.

Here's a simple mouse over event.

click me

Here's the HTML code:

<div id="e83301">click me</div>

Here's the JavaScript code:

const ff = ((e) => { e.target.innerHTML = "yes"});

const ele = document .getElementById("e83301");

ele.addEventListener("click", ff);

This is a simple example of a Event. The event is "click". When user clicks, the browser fires the event, then calls the function attached to that event. (function for this purpose is called the “event handler”.)

addEventListener

node.addEventListener(event_name, function_name)

Adds a event handler.

event_name is a string representing a event.

function_name is a function that will be called when the event happens.

The event handler function function_name is passed a event object as argument.

The element that fired the event can be accessed by the property key "target". That is, event_object.target.

[see JS: What's “this” in a event handler?]

removeEventListener

node.removeEventListener(event_name, function_name)

List of Event Names

https://developer.mozilla.org/en-US/docs/Web/Events

https://www.w3.org/TR/DOM-Level-3-Events/

Web Scripting Overview

  1. Browser Window Object, DOM
  2. Intro to Event-Based Programing
  3. JavaScript Load Order

DOM How-To

  1. Basic DOM Methods
  2. Get Element by ID, Tag, Name, Class, CSS
  3. Change CSS
  4. Change Node Content
  5. Create/Insert Node
  6. Remove Node
  7. Get Attribute Value
  8. Set Attribute Value
  9. Remove Attribute
  10. List/Add/Remove Class Attribute
  11. Add/Remove Event Handler
  12. Navigate DOM Tree
  13. Node Type, Name, Value

DOM HTML GUI

  1. Button
  2. Input Text Field
  3. Password Text Field
  4. Textarea
  5. Radio Button
  6. Checkbox
  7. Selection, Popup Menu
  8. Input Range Slider
  9. Color Picker

Web Scripting Examples

  1. Disable Right Click
  2. document.write
  3. Image Rollover
  4. Pop-up New Window
  5. Digital Clock
  6. Stopwatch
  7. Fade a Element
  8. How to Create Tooltip
  9. Falling Snow Effect
  10. Box Following Scroll

Web Scripting Misc

  1. Web Cookies
  2. Web Storage
  3. DOM: Open URL window.open
  4. Encode URL, Escape String
  5. Browser Info, Navigator Object
  6. Get URL (window.location)
  7. Find Window Width
  8. Find Element Width
  9. WebSocket
  10. Value of “this” in Event Handler
  11. Event Delegation
  12. Get Current Script Tag
  13. insertAfter Element
  14. Randomize List
  15. create Document Fragment
  16. innerHTML, nodeValue, textContent, innerText?
  17. What is Live Object
  18. NodeList vs HTMLCollection
  19. Whitespace Nodes

jQuery

  1. jQuery Basics
  2. jQuery() vs querySelectorAll()
  3. Write JQuery Plugin

node.js

Like it? Help me by telling your friends. Or, Put $5 at patreon.

Or, Buy JavaScript in Depth

If you have a question, put $5 at patreon and message me.

Web Dev Tutorials

  1. HTML
  2. Visual CSS
  3. JS in Depth
  4. JS Object Ref
  5. DOM Scripting
  6. SVG
  7. Blog