本文实例讲述了PHP正则验证Email的方法。分享给大家供大家参考。具体如下：
PHP;">
PHP
function validateEmail($email)
{
$isValid = true;
$atIndex = strrpos($email,"@");
if (is_bool($atIndex) && !$atIndex)
{
$isValid = false;
}
else
{
$domain = substr($email,$atIndex+1);
$local = substr($email,$atIndex);
$localLen = strlen($local);
$domainLen = strlen($domain);
if ($localLen < 1 || $localLen > 64)
{
// local part length exceeded
$isValid = false;
}
else if ($domainLen < 1 || $domainLen > 255)
{
// domain part length exceeded
$isValid = false;
}
else if ($local[0] == '.' || $local[$localLen-1] == '.')
{
// local part starts or ends with '.'
$isValid = false;
}
else if (preg_match('/\\.\\./',$local))
{
// local part has two consecutive dots
$isValid = false;
}
else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/',$domain))
{
// character not valid in domain part
$isValid = false;
}
else if (preg_match('/\\.\\./',$domain))
{
// domain part has two consecutive dots
$isValid = false;
}
else if(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',str_replace("\\\\","",$local)))
{
// character not valid in local part unless
// local part is quoted
if (!preg_match('/^"(\\\\"|[^"])+"$/',$local)))
{
$isValid = false;
}
}
if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
{
// domain not found in DNS
$isValid = false;
}
}
return $isValid;
}
?>
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：
正则表达式在线生成工具：
希望本文所述对大家的PHP程序设计有所帮助。
原文链接：https://www.f2er.com/php/21781.html