<style>
.app{
width: 400px;
height: 400px;
border: 5px solid yellow;
margin: auto;
text-align: center;
}
p{
color: red;
font-size: 12px;
}
</style>
</head>
<body>
<!-- -->
<div class="app">
<h2>注册</h2>
<!-- 账号 -->
<div>
账号:<input type="text" value="" id="txt">
<p id="error"> </p>
</div>
<!-- 密码 -->
<div>
密码:<input type="password" id="pas" value="">
<p id="error1"> </p>
</div>
<!-- 手机号 -->
<div>
手机号:<input type="text" id="txt2" value="">
<p id="error2"> </p>
</div>
<!-- 按钮 -->
<button type="submit" id="but">提交</button>
</div>
js部分
<script>
// 获取元素
var otxt=document.getElementById("txt")
var opas=document.getElementById("pas")
var otxt2=document.getElementById("txt2")
var obut=document.getElementById("but")
var oerr=document.getElementById("error")
var oerr1=document.getElementById("error1")
var oerr2=document.getElementById("error2")
// 定义正则表达式
var atxt=/[0-9]{3,6}/
var apas=/[0-9]{3,6}/
var atxt2=/[0-9]{11}/
// 点击提交按钮事件
obut.onclick=function(){
// 判断是否符合正则表达式条件
if(atxt.test(otxt.value)){
oerr.innerHTML=" ";
}else{
oerr.innerHTML="错误";
}
if(apas.test(opas.value)){
oerr1.innerHTML=" ";
}else{
oerr1.innerHTML="错误";
}
if(atxt2.test(otxt2.value)){
oerr2.innerHTML=" ";
}else{
oerr2.innerHTML="错误";
}
}
</script>
效果图