备注

二进制安全字符串比较(区分大小)：int strcmp(string $str1, string $str2)

注意：$str1小于$str2返回<0,如果$str1大于$str2返回>0,如果两者相等，返回0

strip_tags:从字符串中去除HTML和PHP标记

1.注册页面

<?php
$string = ‘qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM0123456789’;
$code = ”;
for ($i=1;$i<=4;$i++){
$code.='<span style="color:rgb(‘.mt_rand(0,255).’,’.mt_rand(0,255).’,’.mt_rand(0,255).’)">’.$string[mt_rand(0,strlen($string)-1)].'</span>’;
}
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>注册页面</title>
</head>
<body>
    <h1 align="center">笨猪注册页面</h1>
    <form method="post" action="doAction.php">
    <table border="1" cellpadding="0" cellspacing="0" width="50%" bgcolor="#ABCDEF" align="center">
        <tr>
        <td align="right">用户名</td>
        <td><input type="text" name="username" placeholder="请输入合法用户名…"/>
        </td>
        </tr>
        <tr>
        <td align="right">密码</td>
        <td><input type="password" name="password" placeholder="请输入密码…"/></td>
        </tr>
        <tr>
        <td align="right">确认密码</td>
        <td><input type="password" name="passwords" placeholder="请确认密码…"/></td>
        </tr>
        <tr>
        <td align="right">邮箱</td>
        <td><input type="text" name="email" placeholder="请输入合法的邮箱…"/></td>
        </tr>
        <tr>
        <td align="right">兴趣爱好</td>
        <td>
        <input type="checkbox" name="fav[]" id="" value="PHP" />PHP
        <input type="checkbox" name="fav[]" id="" value="JAVA" />JAVA
        <input type="checkbox" name="fav[]" id="" value="PYTHON" />PYTHON
        <input type="checkbox" name="fav[]" id="" value="GO" />GO
        <input type="checkbox" name="fav[]" id="" value="Android" />Android
        <input type="checkbox" name="fav[]" id="" value="C" />C
        <input type="checkbox" name="fav[]" id="" value="C++" />C++
        </td>
        </tr>
        <tr>
        <td align="right">验证码</td>
        <td><input type="text" name="verify" /><?PHP echo $code; ?>
        <input type="hidden" name="verifys" value="<?PHP echo strip_tags($code); ?>"/>
        </td>
        </tr>
        <tr>
        <td colspan="2" align="center"><input type="submit" value="注册" /></td>
        </tr>
    </table>
    </form>
</body>
</html>

2.处理页面

<?php
//防止中文乱码
header('content-type:text/html;charset=utf-8');
$username = $_POST['username'];
$password = $_POST['password'];
$passwords = $_POST['passwords'];
$email = $_POST['email'];
$fav = $_POST['fav'];
//统一转成小写进行比较
$verify = strtolower($_POST['verify']);
$verifys = strtolower($_POST['verifys']);
$redirectUrl = '<a href="register.php">重新注册</a>';

//判断用户名是否为空
if(strlen($username)==0){
exit('请输入用户名<br/>'.$redirectUrl);
}else{
    //判断用户名是否为字母开头
    $ascii = ord($username{0});
    //检测ascii码是否在65-90（A-Z）或者97-122(a-z)
    if(!(($ascii>=65&&$ascii<=90)||($ascii>=97&&$ascii<=122))){
    exit('用户名首字母需要以字母开始<br/>'.$redirectUrl);
    }
}

//判断密码是否为空
if(strlen($password)==0){
    exit('请输入密码<br/>'.$redirectUrl);
}else{
    if(strlen($password<6)){
    exit('密码长度不符合规范<br/>'.$redirectUrl);
    }
}

//确认密码是否为空
if(strlen($passwords)==0){
    exit('请输入确认密码<br/>'.$redirectUrl);
}else{
    if($password !== $passwords){
    exit('两次输入的密码不一致<br/>'.$redirectUrl);
    }
}

//判断邮箱是否为空
if(strlen($email) == 0){
    exit('请输入邮箱<br/>'.$redirectUrl);
}else{
//判断是否有@
    if(strpos($email,'@') == false){
    exit('邮箱不合法<br/>'.$redirectUrl);
    }
}

//验证码是否为空
if(strlen($verify) == 0){
    exit('请输入验证码<br/>'.$redirectUrl);
}else{
    //判断验证码是否正确
    if($verify !== $verifys){
    exit('验证码输入不正确<br/>'.$redirectUrl);
    }
}

if(!empty($fav)){
    //将数组转换成字符串
    $favstr = join(',',$fav);
}
$passwordMd5 = md5($password);
echo '恭喜注册成功，用户信息如下:<br/>';
$userinfo = <<<EOF
    <table align="center" border="1" cellspacing="0" cellpadding="0" width="50%">
        <tr>
        <td>用户名</td>
        <td>密码</td>
        <td>邮箱</td>
        <td>兴趣爱好</td>
        </tr>
        <tr>
        <td>{$username}</td>
        <td>{$passwordMd5}</td>
        <td>{$email}</td>
        <td>{$favstr}</td>
        </tr>
    </table>
EOF;

echo $userinfo;
?>

效果图：