一、修改样式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<!--修改样式-->
<input type="button" value="修改样式" id="btn">
<div id="dv"></div>
<script>
let btn = document.getElementById("btn");
btn.onclick=function(){
let dv = document.getElementById("dv");
dv.style.width="300px";
dv.style.height="300px";
dv.style.backgroundColor = "pink";
}
</script>
</body>
</html>
二、获取类样式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.cls{
width: 300px;
height: 300px;
background-color: pink;
}
</style>
</head>
<body>
<!--获取类样式-->
<input type="button" value="修改样式" id="btn">
<div id="dv"></div>
<script>
let btn = document.getElementById("btn");
btn.onclick = function(){
//在js中操作类 className 公式 cls不要加点
document.getElementById("dv").className = "cls";//"cls"前面不要加点
}
</script>
</body>
</html>
三、用className实现一个按钮显示和隐藏
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div{
width: 300px;
height: 200px;
background-color: skyblue;
}
.cls{
/*这个类是控制隐藏的*/
display: none;
}
</style>
</head>
<body>
<!--用className实现一个按钮显示和隐藏-->
<input type="button" value="隐藏" id="btn">
<div id="dv" class="cls"></div>
<script>
let btn = document.getElementById("btn");
btn.onclick = function(){
//console.log(document.getElementById("dv").className);这里面的如果对象有class类,会返回其class对象,如果没有就为空
if(document.getElementById("dv").className!="cls"){
document.getElementById("dv").className = "cls";
this.value = "显示";
}
else{
document.getElementById("dv").className = "";
this.value = "隐藏";
}
}
</script>
</body>
</html>
四、网页开关灯
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.cls{
background-color: black;
}
</style>
</head>
<body>
<!--网页开关灯-->
<input type="button" value="开/关灯" id="btn">
<script>
//获取body标签 document.body 能拿到body标签的
let btn = document.getElementById("btn");
btn.onclick = function(){
document.body.className = document.body.className !='cls'?"cls":"";
}
</script>
</body>
</html>
五、修改列表
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<!--修改列表-->
<input type="button" value="变背景色" id="btn">
<ul id="uu">
<li>卡卡西</li>
<li>大蛇丸</li>
<li>我爱罗</li>
<li>鸣人</li>
<li>佐助</li>
</ul>
<script>
let btn = document.getElementById("btn");
btn.onclick = function(){
document.getElementById("uu").style.backgroundColor = "skyblue";
}
</script>
</body>
</html>
六、阻止a链接 跳转
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<!--阻止a链接 跳转-->
<!--<a href="https://www.baidu.com" onclick="alert('我被点击了'); return false">百度</a>-->
<a href="https://www.baidu.com" id="ak">百度</a>
<script>
//阻止a链接跳转 return false
let ak = document.getElementById("ak");
ak.onclick = function(){
alert("我被点击了");
return false;
}
</script>
</body>
</html>
七、点击小图变大图
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<!--点击小图变大图-->
<a href="images/1.jpg" id="ak"><img src="images/2.jpg" alt=""></a>
<img src="" alt="" id="big">
<script>
let ak = document.getElementById("ak");
ak.onclick = function(){
document.getElementById("big").src = this.href;
return false;//不允许跳转
}
</script>
</body>
</html>
八、相册模板
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
body{
font-family: "宋体";
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;
}
#imagegallery{
list-style: none;
}
#imagegallery li{
margin: 0px 20px 20px 0px;
padding: 0px;
display: inline;
}
#imagegallery li a img{
border:0;
}
</style>
</head>
<body>
<!--相册模板-->
<h2>
美女画廊
</h2>
<ul id="imagegallery">
<li><a href="images/4.jpg" title="美女A">
<img src="images/4-small.jpg" width="100" alt="美女1"/>
</a></li>
<li><a href="images/5.jpg" title="美女B">
<img src="images/5-small.jpg" width="100" alt="美女2"/>
</a></li>
<li><a href="images/6.jpg" title="美女C">
<img src="images/6-small.jpg" width="100" alt="美女3"/>
</a></li>
<li><a href="images/7.jpg" title="美女D">
<img src="images/7-small.jpg" width="100" alt="美女4"/>
</a></li>
</ul>
<div style="clear: both"></div>
<!--显示大图的-->
<img id="image" src="images/under.jpg" alt="" width="450"/>
<p id="des">选择一个图片</p>
<script>
//从ul的标签获取所有的a标签
let aObjs = document.getElementById("imagegallery").getElementsByTagName("a");
for(let i=0;i<aObjs.length;i++){
//给每个a链接做点击事件
aObjs[i].onclick = function(){
//获取id为image的标签的src赋值
document.getElementById("image").src = this.href;
//获取id为des的innerText赋值链接的title
document.getElementById("des").innerText = this.title;
return false;
}
}
</script>
</body>
</html>
九、各行换色
//封装一个获取id 的函数
function my$(id){
return document.getElementById(id);
}
将其命名为public.js
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<!--各行换色-->
<input type="button" value="各行换色" id="btn">
<ul id="uu">
<li>红旗</li>
<li>五菱宏光</li>
<li>奔驰</li>
<li>兰博基尼</li>
<li>哈弗</li>
<li>奥迪</li>
</ul>
<script src="public.js"></script>
<script>
my$("btn").onclick = function(){
let list = document.getElementsByTagName("li");
for(let i=0;i<list.length;i++){
if(i % 2 == 0){
list[i].style.backgroundColor = "red";
}
else{
list[i].style.backgroundColor = "yellow";
}
}
}
</script>
</body>
</html>
十、经过列表变色
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
ul{
list-style: none;
cursor: pointer;/*鼠标表变为小手*/
}
</style>
</head>
<body>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
<li>5</li>
<li>6</li>
<li>7</li>
<li>8</li>
</ul>
<script src="public.js"></script>
<script>
let list = document.getElementsByTagName("li");
for(let i=0;i<list.length;i++){
list[i].onmouseover = function(){
this.style.backgroundColor = "pink";
}
list[i].onmouseout = function(){
this.style.backgroundColor = "";
}
}
</script>
</body>
</html>
十一、通过name属性获取元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<!--通过name属性获取元素-->
<input type="button" value="显示按钮" id="btn"><br />
<input type="text" value="完蛋了,语法在一起全混了" name="name1"><br />
<input type="text" value="完蛋了,语法在一起全混了" name="name2"><br />
<input type="text" value="完蛋了,语法在一起全混了" name="name3"><br />
<input type="text" value="完蛋了,语法在一起全混了" name="name1"><br />
<input type="text" value="完蛋了,语法在一起全混了" name="name1"><br />
<input type="text" value="完蛋了,语法在一起全混了" name="name1"><br />
<script src="public.js"></script>
<script>
my$("btn").onclick = function(){
let inputs = document.getElementsByName("name1");
for(let i=0;i<inputs.length;i++){
inputs[i].value = "加油,继续学习吧";
}
}
</script>
</body>
</html>
十二、 根据类样式获取元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
div{
width: 300px;
height: 50px;
background-color: pink;
margin-top: 10px;
}
.cls{
background-color: skyblue;
}
</style>
</head>
<body>
<!--根据类样式获取元素-->
<input type="button" value="显示效果" id="btn">
<p class="cls">这是第一个p标签</p>
<p>这是第二个p标签</p>
<span class="cls">这是第一个span标签</span><br />
<span>这是第二个span标签</span><br />
<div class="cls">这是第一个div标签</div>
<div>这是第二个div标签</div>
<script src="public.js"></script>
<script>
//点击按钮带cls的类,将其变色
my$("btn").onclick = function(){
let objs = document.getElementsByClassName("cls");
for(let i = 0;i < objs.length; i++){
objs[i].style.backgroundColor = "red";
}
}
</script>
</body>
</html>
十三、其他方式获取元素
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.cls{
background-color: skyblue;
}
</style>
</head>
<body>
<!--其他方式获取元素-->
<input type="button" value="显示效果" id="btn">
<p class="cls">这是第一个p标签</p>
<p>这是第二个p标签</p>
<div class="cls">这是第一个div标签</div>
<div>这是第二个div标签</div>
<script src="public.js"></script>
<script>
//总结:根据id获取元素方式之前的写法如下:
// let btn = document.getElementById("btn");
// let btnObj = document.querySelector("#btn");//注意这个方式要带选择器 id 就要带 #
// btnObj.onclick = function(){
// alert("666");
// }
let objs = document.querySelectorAll(".cls");//集合
for(let i=0;i<objs.length;i++){
objs[i].style.backgroundColor = "pink";//注意这个方式要带选择器 就要带 .
}
/*
总结:
根据id获取元素
1.document.getElementById("id的属性");
根据标签获取元素
2.document.getElementByTagName("标签名");
根据name名称获取元素
3.document.getElementByName("name的属性名");
根据类样式获取元素
4.document.getElementByClassName("类样式名称");
根据选择器获取元素
5.document.querySelector("#btn")
6.document.querySelectorAll(".cls");
7.document.body 专门获取body的
*/
</script>
</body>
</html>
总结:
根据id获取元素
1.document.getElementById("id的属性");
根据标签获取元素
2.document.getElementByTagName("标签名");
根据name名称获取元素
3.document.getElementByName("name的属性名");
根据类样式获取元素
4.document.getElementByClassName("类样式名称");
根据选择器获取元素
5.document.querySelector("#btn")
6.document.querySelectorAll(".cls");
7.document.body 专门获取body的
十四、鼠标经过显示边框
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
*{
margin: 0;
padding: 0;
}
div{
width: 200px;
height: 150px;
background-color: pink;
float: left;
margin-left: 10px;
border: 2px solid pink;/*避免后面加边框错位*/
}
</style>
</head>
<body>
<!--鼠标经过显示边框-->
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<div></div>
<script src="public.js"></script>
<script>
let divs = document.getElementsByTagName("div");
for(let i=0;i<divs.length;i++){
divs[i].onmouseover = function(){
this.style.border = "2px solid red";
}
divs[i].onmouseout = function(){
this.style.border = "";
}
}
</script>
</body>
</html>
十五、搜索效果
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
input{
color: gray;
/*外面的样式不在变换*/
outline: none;
}
</style>
</head>
<body>
<!--搜索效果-->
<input type="text" value="请输入搜索内容" id="txt">
<script src="public.js"></script>
<script>
//获取焦点事件 onfouse
my$("txt").onfocus = function(){
//判断自己有没有值
if(this.value == "请输入搜索内容"){
this.value = "";
this.style.color = "black";
}
}
//失去焦点onblur
my$("txt").onblur = function(){
//判断
if(this.value == ""){
this.value = "请输入搜索内容";
this.style.color = "gray";
}
}
</script>
</body>