前端学习笔记(带实例)

前端学习笔记

实例:图片自动轮换


<html>
	<head>
		<meta charset="UTF-8">
		<title>title>
		
		<script>
			var index = 0;
			
			function changeImg(){
				
				//1. 获得要切换图片的那个元素
				var img = document.getElementById("img1");
				
				//计算出当前要切换到第几张图片
				var curIndex = index%3 + 1;  //0,1,2 
				img.src="../img/"+curIndex+".jpg";  //1,2,3
				//每切换完,索引加1
				index = index + 1;
			}
			
			function init(){
				
				setInterval("changeImg()",1000);
			}
			
		script>
	head>
	<body onload="init()">
		<img src="../img/1.jpg" width="100%" id="img1"/>
	body>
html>

document.getElementById("****") 获得字段值

实例:表单检查

前端学习笔记(带实例)_第1张图片


<html>
	<head>
		<meta charset="UTF-8">
		<title>title>
		
		<script type="text/javascript" src="../js/regutils.js" >script>
		<script>
			/*
				1. 确定事件 : onfocus
				2. 事件要驱动函数
				3. 函数要干一些事情: 修改span的内容
			*/
			function showTips(spanID,msg){
				//首先要获得要操作元素 span
				var span = document.getElementById(spanID);
				span.innerHTML = msg;
			}
			/*
				校验用户名:
				1.事件: onblur  失去焦点
				2.函数: checkUsername()
				3.函数去显示校验结果
			*/
			function checkUsername(){
				//获取用户输入的内容
				var uValue = document.getElementById("username").value;
				//对输入的内容进行校验
				//获得要显示结果的span
				var span = document.getElementById("span_username");
				if(uValue.length < 6){
					//显示校验结果
					span.innerHTML = "对不起,太短";
					return false;
				}else{
					span.innerHTML = "恭喜您,可用";
					return true;
				}
			}
			
			/*
			 密码校验
			 */
			function checkPassword(){
				//获取密码输入
				var uPass = document.getElementById("password").value;
				
				var span = document.getElementById("span_password");
				
				//对密码输入进行校验
				if(uPass.length < 6){
					span.innerHTML = "对不起,太短";
					return false;
				}else{
					span.innerHTML = "恭喜您,够用";
					return true;
				}
			}
			
			/*
			 确认密码校验
			 * */
			function checkRePassword(){
				//获取密码输入
				var uPass = document.getElementById("password").value;
				
				//获取确认密码输入
				var uRePass = document.getElementById("repassword").value;
				
				
				var span = document.getElementById("span_repassword");
				
				//对密码输入进行校验
				if(uPass != uRePass){
					span.innerHTML = "对不起,两次密码不一致";
					return false;
				}else{
					span.innerHTML = "";
					return true;
				}
			}
			
			/*
			 校验邮箱
			 * */
			function checkMail(){
				var umail = document.getElementById("email").value;
				
				var flag = checkEmail(umail);
				
				var span = document.getElementById("span_email");
				//对邮箱输入进行校验
				if(flag){
					span.innerHTML = "恭喜您,可用";
					return true;
				}else{
					span.innerHTML = "对不起,邮箱格式貌似有问题";
					return false;
				}
			}
			
			function checkForm(){
				var flag = checkUsername() && checkPassword() && checkRePassword() && checkMail();
				return flag;
			}
			
		script>
	head>
	<body>
		<form action="../01-自动轮播图片/图片自动轮播.html" onsubmit="return checkForm()" >
			用户名:<input type="text" id="username" onfocus="showTips('span_username','用户名长度不能小于6')" onblur="checkUsername()" onkeyup="checkUsername()" /><span id="span_username">span><br />
			密码:<input type="password" id="password" onfocus="showTips('span_password','密码长度不能小于6')" onblur="checkPassword()" onkeyup="checkPassword()"/><span id="span_password">span><br />
			确认密码:<input type="password" id="repassword" onfocus="showTips('span_repassword','两次密码必须一致')" onblur="checkRePassword()" onkeyup="checkRePassword()" /><span id="span_repassword">span><br />
			邮箱:<input type="text" id="email" onfocus="showTips('span_email','邮箱格式必须正确')" onblur="checkMail()" /><span id="span_email">span><br />
			手机号:<input type="text" id="text" /><br />
			
			<input type="submit" value="提交" />
		form>
	body>
html>

你可能感兴趣的:(前端)