JS: Image Rollover

By Xah Lee. Date: . Last updated: .

This page shows a JavaScript based image rollover.

Move your mouse to the following image and see it change. (on mobile devices, touch the image also works.)

tile A

Here's the HTML code:

<img id="img_roll_54998" src="i/tile_A.png" alt="tile A">

Here's the JavaScript code:

let obj = document .getElementById("img_roll_54998");

(new Image()).src = "i/tile_B.png"; // pre-cache

obj.addEventListener("mouseover", (() => { obj.src="i/tile_B.png"; }) , false);

obj.addEventListener("mouseout", (() => { obj.src="i/tile_A.png"; }) , false);

How to pre-cache Images?

(new Image()).src = "cats.gif";

the Image() is a constructor that returns a HTMLImageElement object, which represents the <image> element.

Pure CSS Image Rollover

CSS: Image Rollover

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

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Web Dev Tutorials

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