JavaScript DOM编程艺术第四章 — JavaScript图片库案例研究

二森 2021-06-17 16:40:22
编程 javascript DOM 第四章 艺术



<!DOCTYPE html>
<meta charset="utf-8" />
<link rel="stylesheet" href="styles/layout.css" media="screen" />
<script type="text/javascript" src="scripts/showPic.js"></script>
<a href='images/1.jpg' title="黄昏海边" onclick="showPic(this);
return false;">黄昏海边</a>
<a href='images/2.jpg' title="大漠孤烟直" onclick="showPic(this);
return false;">沙漠</a>
<a href='images/3.jpg' title="湖泊" onclick="showPic(this);
return false;">湖泊</a>
<a href='images/4.jpg' title="可爱熊熊" onclick="showPic(this);
return false;">可爱壁纸</a>
<a href='images/5.jpg' title="哆啦A梦" onclick="showPic(this);
return false;">哆啦A梦</a>
<img id="placeholder" src="images/gallery.png" alt="my image gallery" />
<p id="description">Choose an image.</p>


1. childNodes属性

  • 用来获取任何一个元素的所有子元素
  • 使用方式:element.childNodes
  • 返回值:这个元素的所有子元素数组。包含所有类型的节点:元素节点、文本节点和属性节点。(实际上,文档里几乎每个东西都是一个节点,甚至连空格和换行符都是节点)

-- 示例:输出body元素的全体子元素

function countBodyChildren() {
let body_element = document.getElementsByTagName('body')[0];

-- 输出:


-- 文本节点示例:

2. nodeType属性

  • 获取每个节点的type(元素节点、文本节点还是属性节点)
    • 元素节点的nodeType属性值:1
    • 属性节点的nodeType属性值:2
    • 文本节点的nodeType属性值:3
  • 使用方式:node.nodeType

-- 示例

let body_element = document.getElementsByTagName('body')[0];

-- 输出:1

3. nodeValue属性

  • 获取 or 设置节点的值
  • 获取节点的值使用方式:node.nodeValue
  • 设置节点的值使用方式:node.nodeValue = xxx
  • 注意,元素节点的nodeValue值是null。如果想获取p元素所包含的文本值,则需要获取元素所包含的文本值,则需要获取p元素的第一个子节点

-- 示例:输出 p元素的nodeValue 和 p的childNodes 以及 第一个子节点的nodeValue

function countBodyChildren() {
let description = document.getElementsById('description');

--- 输出:

-- 示例:将p元素nodeValue值设置为'hello world'

function countBodyChildren() {
let description = document.getElementById('description');
description.childNodes[0].nodeValue = 'hello world';

--- 输出:

4. firstChild和lastChild属性

  • 指childNodes的第一个元素和最后一个元素,相当于简写,如下:
    • node.firstChild ——> node.childNodes[0]

    • node.lastChild ——> node.childNodes[node.childNodes.length - 1]


1. HTML见上

2. JavaScript

function showPic(whichPic) {
let source = whichPic.getAttribute('href');
let placeholder = document.getElementById('placeholder');
placeholder.setAttribute('src', source);
let title = whichPic.getAttribute('title');
let description = document.getElementById('description');
description.firstChild.nodeValue = title;

3. CSS

body {
font-family: 'Helvetica', 'Arial', serif;
color: #333;
background-color: #ccc;
margin: 1em 10%;
h1 {
color: #333;
background-color: transparent;
a {
color: #c60;
background-color: transparent;
font-weight: bold;
text-decoration: none;
ul {
padding: 0;
li {
float: left;
padding: 1em;
list-style: none;
img {
width: 80%;
display: block;
clear: both;




  • 使用setAttribute:element.setAttribute('value', 'the new value')
  • 使用非DOM解决方案:element.value = 'the new value'



  1. HTML + CSS + JavaScript to achieve cool Fireworks (cloud like particle text 3D opening)
  2. HTML + CSS + JavaScript realizes 520 advertising love tree (including music), which is necessary for programmers to express themselves
  3. Solve the problem of Web front-end deployment server (it can be deployed online without a server)
  4. HTML + CSS + JS make wedding countdown web page template (520 / Tanabata Valentine's Day / programmer advertisement)
  5. What else can driverless minibus do besides "Park connection"?
  6. Cloud native leads the era of all cloud development
  7. NRM mirror source management tool
  8. Bring it to you, flex Jiugong
  9. Lolstyle UI component development practice (II) -- button group component
  10. Deconstruction assignment in ES6
  11. Luo 2 peerless Tang clan was officially launched. The official gave a key point, and the broadcast time was implied
  12. 20初识前端HTML(1)
  13. 当新零售遇上 Serverless
  14. 20 initial knowledge of front-end HTML (1)
  15. When new retail meets serverless
  16. [golang] - go into go language lesson 5 type conversion
  17. [golang] - go into go language lesson 6 conditional expression
  18. HTML5(八)——SVG 之 path 详解
  19. HTML5 (8) -- detailed explanation of SVG path
  20. 需要开通VIP以后页面内容才能复制怎么办?控制台禁用javascript即可
  21. Web前端|CSS入门教程(超详细的CSS使用讲解,适合前端初学者)
  22. 实践积累 —— 用Vue3简单写一个单行横向滚动组件
  23. Serverless 全能选手,再下一城
  24. What if you need to open a VIP to copy the page content? Just disable JavaScript on the console
  25. Web front end | CSS introductory tutorial (super detailed CSS explanation, suitable for front-end beginners)
  26. Practice accumulation - write a single line horizontal scroll component simply with vue3
  27. Dili Reba is thin again. She looks elegant and high in a strapless hollow skirt, and her "palm waist" is beautiful to a new height
  28. Serverless all-round player, next city
  29. The difference between MySQL semi synchronous replication and lossless semi synchronous replication
  30. Vue表单设计器的终极解决方案
  31. The ultimate solution for Vue form designer
  32. Nginx从理论到实践超详细笔记
  33. Yu Shuxin's red backless swimsuit is split to the waist and tail, with a concave convex figure and excessive color matching, and his face is white to dazzling
  34. Nginx ultra detailed notes from theory to practice
  35. 【动画消消乐|CSS】086.炫酷水波浪Loading过渡动画
  36. typecho全站启用https
  37. CCTV has another popular employee. The off-site interpretation is very professional, and the appearance ability is no less than that of Wang Bingbing
  38. [animation Xiaole | CSS] 086. Cool water wave loading transition animation
  39. Enable HTTPS in Typecho
  40. 50天用JavaScript完成50个web项目,我学到了什么?
  41. 根据JavaScript中原生的XMLHttpRequest实现jQuery的Ajax
  42. What have I learned from completing 50 web projects with JavaScript in 50 days?
  43. "My neighbor doesn't grow up" has hit the whole network. There are countless horse music circles, and actor Zhou Xiaochuan has successfully made a circle
  44. 根据JavaScript中原生的XMLHttpRequest实现jQuery的Ajax
  45. Implement the Ajax of jQuery according to the native XMLHttpRequest in JavaScript
  46. Implement the Ajax of jQuery according to the native XMLHttpRequest in JavaScript
  47. 30 + women still wear less T-shirts and jeans. If they wear them like stars, they will lose weight
  48. 数栈技术分享前端篇:TS,看你哪里逃~
  49. Several stack technology sharing front end: TS, see where you escape~
  50. 舍弃Kong和Nginx,Apache APISIX 在趣链科技 BaaS 平台的落地实践
  51. Abandon the landing practice of Kong and nginx, Apache apisik on the baas platform of fun chain technology
  52. 浪迹天涯king教你用elementui做复杂的表格,去处理报表数据(合并表头,合并表体行和列)
  53. 前端HTML两万字图文大总结,快来看看你会多少!【️熬夜整理&建议收藏️】
  54. Wandering around the world king teaches you to use elementui to make complex tables and process report data (merge header, merge table body rows and columns)
  55. 路由刷新数据丢失 - vuex数据读取的问题
  56. Front end HTML 20000 word graphic summary, come and see how much you can【 Stay up late to sort out & suggestions]
  57. Route refresh data loss - vuex data reading problem
  58. Systemctl系统启动Nginx服务脚本
  59. Systemctl system startup nginx service script
  60. sleepless