本文实例讲述了PHP实现的用户注册表单验证功能。分享给大家供大家参考，具体如下：
注册界面
register.html
<h1>用户注册</h1>
<form method="post" action="register_verify.php">
<input type="text" placeholder="用户名" name="username"><br><br>
<input type="password" placeholder="密码" name="password"><br><br>
<input type="password" placeholder="重复密码" name="password2"><br><br>
<label>性别：
<input type="radio" name="sex" value="男" checked="checked">男
<input type="radio" name="sex" value="女">女</label><br><br>
<input type="email" placeholder="邮箱" name="email"><br><br>
<button class="btn" type="submit">注册</button>
</form>
register_verify.php
<?php
require "mysql.php"; //导入mysql.php访问数据库
$username=$_POST['username'];
$password=$_POST['password'];
$password2=$_POST['password2'];
$sex=$_POST['sex'];
$email=$_POST['email'];
if(checkEmpty($username,$password,$password2,$sex,$email)){
if(checkpwd($password,$password2)){
if(checkEmail($email)){
if(insert($username,$password,$sex,$email))
echo"注册成功";
}
}
}
//方法：判断是否为空
function checkEmpty($username,$password,$password2,$sex,$email){
if($username==null||$password==null||$password2==null){
echo '<html><head><Script Language="JavaScript">alert("用户名或密码为空");</Script></head></html>' . "<meta http-equiv=\"refresh\" content=\"0;url=register.html\">";
}
else{
if($sex==null){
echo '<html><head><Script Language="JavaScript">alert("性别为空");</Script></head></html>' . "<meta http-equiv=\"refresh\" content=\"0;url=register.html\">";
}
elseif($email==null){
echo '<html><head><Script Language="JavaScript">alert("邮箱为空");</Script></head></html>' . "<meta http-equiv=\"refresh\" content=\"0;url=register.html\">";
}
else{
return true;
}
}
}
//方法：检查两次密码是否相同
function checkpwd($password,$password2){
if($password==$password2)
return true;
else
echo '<html><head><Script Language="JavaScript">alert("两次密码不一致");</Script></head></html>' . "<meta http-equiv=\"refresh\" content=\"0;url=register.html\">";
}
//方法：邮箱格式验证
function checkEmail($email){
$preg = '/^(\w{1,25})@(\w{1,16})(\.(\w{1,4})){1,3}$/';
if(preg_match($preg, $email)){
return true;
}else{
echo '<html><head><Script Language="JavaScript">alert("邮箱格式有误");</Script></head></html>' . "<meta http-equiv=\"refresh\" content=\"0;url=register.html\">";
}
}
//方法：将数据插入数据库中
function insert($username,$password,$sex,$email){
$conn=new Mysql();
$sql="insert into user VALUE (null,'$username','$password','$sex','$email')";
$result=$conn->sql($sql);
if($result){
return true;
}
else{
echo '<html><head><Script Language="JavaScript">alert("写入数据库失败");</Script></head></html>' . "<meta http-equiv=\"refresh\" content=\"0;url=register.html\">";
}
$conn->close();
}
验证码和数据库的实现方法前面写过，这里不再赘述。
可参考前面两篇文章：
PHP封装mysqli基于面向对象的mysql数据库操作类
PHP通过GD库实现验证码功能
PS：这里再为大家提供2款非常方便的正则表达式工具供大家参考使用：
JavaScript正则表达式在线测试工具： http://tools.jb51.net/regex/javascript
正则表达式在线生成工具： http://tools.jb51.net/regex/create_reg