今天学习了DOM操作与实战案例
代码：
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>根据id选择元素</title>
</head>
<body>
<ul id="lists">
<li id="item1">列表项01</li>
<li>列表项02</li>
<li id="item2">列表项03</li>
<li>列表项04</li>
<li id="item3">列表项05</li>
</ul>
<script>
let item1=document.getElementById('item1');
let item2=document.getElementById('item2');
let item3=document.getElementById('item3');
item1.style.backgroundColor='yellow';
item2.style.backgroundColor='yellow';
item3.style.backgroundColor='yellow';
function getElements() {
let elements={};
for(let i=0;i<arguments.length;i++){
let id=arguments[i];
let elt=document.getElementById(id);
if(elt===null){
throw new Error("No element with id: "+id);
}
elements[id]=elt;
}
return elements;
}
let elements=getElements('item1','item2','item3');
for(let key in elements){
elements[key].style.backgroundColor='coral';
}
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>根据标签名Tag来获取元素<</title>
</head>
<body>
<ul>
<li>列表项01</li>
<li>列表项02</li>
<li>列表项03</li>
<li>列表项04</li>
<li>列表项05</li>
</ul>
<script>
let ul=document.getElementsByTagName('ul')[0];
ul.style.backgroundColor='lightgreen';
//let ul1=document.getElementsByTagName('ul').item(0);
//ul1.style.backgroundColor='lightblue';
let lists=document.getElementsByTagName('li');
console.log(lists);
for(let i=0;i<lists.length;i++){
console.log(lists);
for(let i=0;i<lists.length;i++){
lists[i].style.backgroundColor='lightpink';
}
let ul2=document.getElementsByTagName('ul').item(0);
let item2=ul2.getElementsByTagName('li').item(1);
item2.style.backgroundColor='green';
}
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>根据标签名Tag来获取元素<</title>
</head>
<body>
<ul>
<li>列表项01</li>
<li>列表项02</li>
<li>列表项03</li>
<li>列表项04</li>
<li>列表项05</li>
</ul>
<script>
let ul=document.getElementsByTagName('ul')[0];
ul.style.backgroundColor='lightgreen';
//let ul1=document.getElementsByTagName('ul').item(0);
//ul1.style.backgroundColor='lightblue';
let lists=document.getElementsByTagName('li');
console.log(lists);
for(let i=0;i<lists.length;i++){
console.log(lists);
for(let i=0;i<lists.length;i++){
lists[i].style.backgroundColor='lightpink';
}
let ul2=document.getElementsByTagName('ul').item(0);
let item2=ul2.getElementsByTagName('li').item(1);
item2.style.backgroundColor='green';
}
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>根据标签名Tag来获取元素<</title>
</head>
<body>
<ul>
<li>列表项01</li>
<li>列表项02</li>
<li>列表项03</li>
<li>列表项04</li>
<li>列表项05</li>
</ul>
<script>
let ul=document.getElementsByTagName('ul')[0];
ul.style.backgroundColor='lightgreen';
//let ul1=document.getElementsByTagName('ul').item(0);
//ul1.style.backgroundColor='lightblue';
let lists=document.getElementsByTagName('li');
console.log(lists);
for(let i=0;i<lists.length;i++){
console.log(lists);
for(let i=0;i<lists.length;i++){
lists[i].style.backgroundColor='lightpink';
}
let ul2=document.getElementsByTagName('ul').item(0);
let item2=ul2.getElementsByTagName('li').item(1);
item2.style.backgroundColor='green';
}
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>通过class属性选取元素</title>
</head>
<body>
<ul class="ul">
<li class="red">列表项01</li>
<li>列表项02</li>
<li class="green">列表项03</li>
<li>列表项04</li>
<li class="coral large">列表项05</li>
</ul>
<script>
let red=document.getElementsByClassName('red');
console.log(red);
red[0].style.backgroundColor='red';
document.getElementsByClassName('ul').item(0).getElementsByClassName('green').item(0).style.backgroundColor='green';
let large=document.getElementsByClassName('coral large')[0];
large.style.backgroundColor='coral';
large.style.fontSize='1.5rem';
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>使用css选择器来获取元素</title>
</head>
<body>
<ul id="ul">
<li class="red">列表项01</li>
<li>列表项02</li>
<li class="green">列表项03</li>
<li class="green">列表项04</li>
<li class="coral large">列表项05</li>
</ul>
<script>
let lists=document.querySelectorAll('li');
console.log(lists);
let ul=document.querySelector('#ul');
console.log(ul);
let li=ul.querySelectorAll('.green');
for(let i=0;i<li.length;i++){
li[i].style.backgroundColor='green';
}
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>模拟智能在线kefu</title>
<style>
div:nth-child(1){
width:450px;
height: 650px;
background-color:lightblue;
margin:30px auto;
color:#333;
box-shadow: 2px 2px 2px #808080;
}
h2{
text-align: center;
margin-bottom:-10px;
}
div:nth-child(2){
width:400px;
height: 500px;
border:4px double green;
background-color: #efefef;
margin:20px auto 10px;
}
ul{
list-style: none;
line-height:2em;
overflow: hidden;
padding: 15px;
}
table{
width:90%;
height: 80px;
margin: auto;
}
textarea{
border: none;
resize: none;
background: lightyellow;
}
button{
width: 60px;
height:40px;
background-color: seagreen;
color:white;
border:none;
}
button:hover{
cursor: pointer;
background-color: orange;
}
</style>
</head>
<body>
<div>
<h2>在线kefu</h2>
<div>
<ul>
<li></li>
</ul>
</div>
<table>
<tr>
<td align="right"><textarea name="text" id="" cols="50" rows="4"></textarea></td>
<td align="left"><button type="button">发现</button></td>
</tr>
</table>
</div>
<script>
let btn=document.getElementsByTagName('button')[0];
let text=document.getElementsByName('text')[0];
let list=document.getElementsByTagName('ul')[0];
let sum=0;
btn.onclick=function () {
if(text.value.length===0){
alert('客官:是不是忘记输入内容了~~');
return false;
}
let userComment=text.value;
text.value='';
let li=document.createElement('li');
li.innerHTML=userComment;
let userPic='<img src="inc/peter.jpg" width="30" style="border-radius: 50%">';
li.innerHTML=userPic+' '+userComment;
list.appendChild(li);
sum+=1;
setTimeout(function () {
let info = [
'真烦人,有话快说,别耽误我玩抖音',
'除了退货,退款,咱们什么都可以聊',
'说啥,本姑娘怎么听不懂呢?再说一遍',
'在我方便的时候再回复你吧~~',
'投诉我的人多了,你算老几~~~'
];
let temp = info[Math.floor(Math.random()*3)];
//取1-5之间的一个整数:Math.floor(Math.random()*6 + 1)
let reply = document.createElement('li');
let kefuPic = '<img src="inc/zly.jpg" width="30" style="border-radius:50%;">';
reply.innerHTML = kefuPic + ' ' + '<span style="color:red">'+temp+'</span>';
list.appendChild(reply);
sum += 1;
},2000);
if (sum > 10) {
list.innerHTML = '';
sum = 0;
}
}
</script>
</body>
</html>运行实例 »
点击 "运行实例" 按钮查看在线实例
