JavaScript表单验证完美代码

用原生JS写一个简单的表单验证

首先，是html部分

<div class="divAll">
   <div id="titles">新用户注册</div>
   <div id="contents">
   <h3>基本信息</h3>
   <hr width="95%" color="#f2f2f2"/>
   <form action="#" onSubmit="return checkForm()">
    <div id="form-itemGroup">
      <label for="userName">用户名：</label>
      <input type="text" id="userName" class="userName" onBlur="checkUserName()" oninput="checkUserName()">
      <span class="default" id="nameErr">请输入至少3位的用户名</span>
    </div>
    <div id="form-itemGroup">
      <label for="userPasword">密码：</label>
      <input type="password" id="userPasword" class="userName" onBlur="checkPassword()" oninput="checkPassword()">
      <span class="default" id="passwordErr">请输入4到8位的密码</span>
    </div>
    <div id="form-itemGroup">
      <label for="userConfirmPasword">确认密码：</label>
      <input type="password" id="userConfirmPasword" class="userName" onBlur="ConfirmPassword()" oninput="ConfirmPassword()">
      <span class="default" id="conPasswordErr">请再输入一遍密码</span>
    </div>
    <div id="form-itemGroup">
      <label for="userPhone">手机号码：</label>
      <input type="text" id="userPhone" class="userName" onBlur="checkPhone()" oninput="checkPhone()">
      <span class="default" id="phoneErr">请输入11位手机号码</span>
    </div>
    <div>
     <button type="submit" class="divBtn">注册</button>
    </div>
   </form>
   </div>
 </div> 

接着，为其加上CSS样式

<style type="text/css">
 .divAll{
   width:800px;
   font-family:'黑体';
   margin:50px auto;
   }
 #titles{
   font-weight:bold;
   font-size:18px;
   height:50px;
   line-height:50px;
   background:#FFF9F3;
   text-align:center;
   border:1px solid #CCC;;
   }
 #contents{
    margin-top:20px;
    background:#FFF9F3;
    border:1px solid #CCC;;
    }
  #form-itemGroup{
   padding:10px;
    }
  #form-itemGroup label{
    display:inline-block;
    width:100px;
    height:32px;
    line-height:32px;
    color:#666;
    text-align:right;
    }
  #form-itemGroup .userName{
    width:200px;
    height:40px;
    line-height:40px;
    border:1px solid #CCC;
    }
  #form-itemGroup .default{
    width:200px;
    height:32px;
    line-height:32px;
    color:#999;
    }
  #form-itemGroup .error{
    height:32px;
    line-height:32px;
    color:#F00;
    }
  #form-itemGroup .success{
    height:32px;
    line-height:32px;
    color:#096;
    }
  .divBtn{
    margin-top:20px;
    margin-left:200px;
    width:100px;
    height:32px;
    line-height:32px;
    background-color:#F93;
    margin-bottom:10px;
    color:#ffffff;
    font-weight:bold;
    border:none;
    }
</style> 

最后是JS部分

<script type="text/javascript">
 function checkForm(){
  var nametip = checkUserName();
  var passtip = checkPassword();
  var conpasstip = ConfirmPassword();
  var phonetip = checkPhone();
  return nametip && passtip && conpasstip && phonetip;
  }
  //验证用户名
  function checkUserName(){
  var username = document.getElementById('userName');
  var errname = document.getElementById('nameErr');
  var pattern = /^\w{3,}$/;  //用户名格式正则表达式：用户名要至少三位
  if(username.value.length == 0){
    errname.innerHTML="用户名不能为空"
    errname.className="error"
    return false;
    }
  if(!pattern.test(username.value)){
    errname.innerHTML="用户名不合规范"
    errname.className="error"
    return false;
    }
   else{
     errname.innerHTML="OK"
     errname.className="success";
     return true;
     }
  }
  //验证密码
function checkPassword(){
  var userpasswd = document.getElementById('userPasword');
  var errPasswd = document.getElementById('passwordErr');
  var pattern = /^\w{4,8}$/; //密码要在4-8位
  if(!pattern.test(userpasswd.value)){
    errPasswd.innerHTML="密码不合规范"
    errPasswd.className="error"
    return false;
    }
   else{
     errPasswd.innerHTML="OK"
     errPasswd.className="success";
     return true;
     }
  }
  //确认密码
  function ConfirmPassword(){
  var userpasswd = document.getElementById('userPasword');
  var userConPassword = document.getElementById('userConfirmPasword');
  var errConPasswd = document.getElementById('conPasswordErr');
  if((userpasswd.value)!=(userConPassword.value) || userConPassword.value.length == 0){
    errConPasswd.innerHTML="上下密码不一致"
    errConPasswd.className="error"
    return false;
    }
   else{
     errConPasswd.innerHTML="OK"
     errConPasswd.className="success";
     return true;
     }
  }
//验证手机号
  function checkPhone(){
  var userphone = document.getElementById('userPhone');
  var phonrErr = document.getElementById('phoneErr');
  var pattern = /^1[34578]\d{9}$/; //验证手机号正则表达式
  if(!pattern.test(userphone.value)){
    phonrErr.innerHTML="手机号码不合规范"
    phonrErr.className="error"
    return false;
    }
   else{
     phonrErr.innerHTML="OK"
     phonrErr.className="success";
     return true;
     }
  }
</script> 

好了，打开浏览器测试一下吧

填写数据，可以！

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