HTML注册表单前端JS验证实现详解

HTML注册表单前端JS验证实现详解

开发一个用于收集用户注册信息的HTML页面，包含姓名（必填）、年龄（需大于17岁）、体重（范围30-150kg）、班级（下拉选择）、登录密码（至少8位）、确认密码（需与登录密码一致）、Email（必填）、电话、QQ及个人简历等字段。针对上述表单元素编写相应的验证逻辑，若检测到输入错误，则在输入框后方以红色字体显示具体错误信息。该实现涉及单行文本输入框text、下拉列表框select、密码输入框password以及多行文本输入框textarea等常用HTML元素，构成一个具备实用性的用户注册表单。

register.html文件结构如下：

 
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>实验2</title>
<link href="check.css" rel="stylesheet" type="text/css">
<script type="text/javascript" src="load.js">
</script>
</head>
<!--return validate()和validate()在于是否清空表单-->
<body onload="load_greeting()">
<form id="test" align="left" onSubmit="return validate()">
<table>
<tr>
<td>Name*:</td>
<td><input type="text" name="Name" id="name" size="20" onChange='check("name")'></td>
<td id="nameCheck" class="check" hidden="true">*姓名不能为空</td>
</tr>
<tr>
<td>Age:</td>
<td><input type="text" name="Age" id="age" size="20" onChange='check("age")'></td>
<td id="ageCheck" class="check" hidden="true">*年龄不能小于17岁</td>
</tr>
<tr >
<td>weight:</td>
<td><input type="text" name="weight" id="weight" size="20" onChange='check("weight")'></td>
<td id="weightCheck" class="check" hidden="true">*体重范围为30~150KG</td>
</tr>
<tr>
<td>Class:</td>
<td><select id="class" name="class">
<option>class0</option>
<option>class1</option>
<option>class2</option>
<option>class3</option>
</select>
</td>
</tr>
<tr>
<td>Password*:</td>
<td><input type="password" name="Password" id="password" size="20" onChange='check("password")'></td>
<td id="passwordCheck" class="check" hidden="true">*password length less than 8</td>
</tr>
<tr>
<td>Confirm Password*:</td>
<td><input type="password" name="cpassword" id="cpassword" size="20" onChange='check("cpassword")'></td>
<td id="cpasswordCheck" class="check" hidden="true">*Two passwd is not same</td>
</tr>
<tr >
<td>Email*:</td>
<td><input type="email" name="email" id="email" size="20" onChange='check(this.id)'></td>
<td id="emailCheck" class="check" hidden="true">*电子邮件名非法！</td>
</tr>
<tr>
<td>TEL:</td>
<td><input type="text" name="TEL" id="TEL" size="20"></td>
</tr>
<tr>
<td>QQ:</td>
<td><input type="text" name="QQ" id="QQ" size="20"></td>
</tr>
<tr>
<td>Personal Information:</td>
<td><textarea rows="10" cols="19"></textarea></td>
</tr>
<tr>
<td colspan="3">
<input type="submit" name="submit">
<input type="reset" name="reset">
</td>
</tr>
</table>
</form>
</body>
</html>

check.css样式定义如下：

 
td.check{
color:#C00;
font-weight:bold;
} 

load.js脚本逻辑如下：

 
function check(str)
{ 
var x = document.getElementById(str);
var y = document.getElementById(str+"Check");
//alert("check!");
if(str=="name")
{ 
if(x.value=="")
y.hidden = false;
else
y.hidden = true;
} 
else if(str=="age")
{ 
if(isNaN(x.value) || x.value < 17)
y.hidden = false;
else
y.hidden = true;
} 
else if(str=="weight")
{ 
x = x.value;
if(isNaN(x) || x < 30 || x > 150)
y.hidden = false;
else
y.hidden = true;
} 
else if(str=="password")
{ 
x = x.value.length;
if(x < 8)
{ 
y.hidden = false;
//alert("check!");
} 
else
y.hidden = true;
} 
else if(str=="cpassword")
{ 
var z = document.getElementById("password").value;
x = x.value;
if(x != z)
y.hidden = false;
else
y.hidden = true;
} 
else if(str=="email")
{ 
x = x.value.indexOf("@")
if(x == -1)
y.hidden = false;
else
y.hidden = true;
} 
return y.hidden;
} 
function validate()
{ 
var arr=["name", "age", "weight", "password", "cpassword", "email"];
var i = 0;
submitOK = true;
while(i <= 5)
{ 
if(!check(arr[i]))
{ 
alert(arr[i]+" wrong!");
submitOK = false;
break;
} 
i++;
} 
if(submitOK)
{ 
alert("提交成功！");
return true;
} 
else
{ 
alert("提交失败");
return false;
} 
} 
function load_greeting()
{ 
//alert("visit \n");
}