【PHP】强大的filter_var

猫哥写代码时候经常会遇到各种需要判断的：

• 判断是否数字；
• 判断是否字符串；
• 判断是否合法email；
• 判断是否IPv4地址；
• ......

从前总会傻傻地写各种正则表达式，虽然正则水平有所提高，但是效率低吖~

直到有一天猫哥发现了filter_var这个强大的工具！之前的猫哥哭晕在厕所...

官网文档：http://php.net/manual/en/function.filter-var.php

来看一系列栗子：

<?php # coding: utf-8

$ip = "1.2.3.4";
if(filter_var($ip, FILTER_VALIDATE_IP)) {
	echo $ip." is valid IP <br>";
} else {
	echo $ip." is not valid IP. <br>";
}

$ip = "311.2.3.4";
//判断是否是合法的IPv4 IP地址
if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
	echo "Second paragraph...<br>";
	echo $ip." is valid IP <br>";
} else {
	echo $ip." is not valid IP <br>";
}

$ip = "10.1.1.1"; //192.168.1.1 这类的一样...
//判断是否是合法的公共IPv4地址
if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE)) {
	echo $ip." is public IPv4 <br>";
} else {
	echo $ip." is not public IPv4 <br>";
}

$ip = "FF01::101";
//判断是否是合法的IPv6地址
if(filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE)) {
	echo $ip." is valid IPv6 <br>";
} else {
	echo $ip." is not valid IPv6 <br>";
}

$email = "a@bc.cn";
//判断是否是public IPv4 IP或者是合法的Public IPv6 IP地址
if(filter_var($email, FILTER_VALIDATE_EMAIL)) {
	echo $email." is a valid email. <br>";
} else {
	echo $email." is not valid email. <br>";
}

$url = "http://blog.csdn.net/972301/article/details/50654449";
if(filter_var($url, FILTER_VALIDATE_URL)) {
	echo $url." is a valid url. <br>";
} else {
	echo $url." is not valid url. <br>";
}

$mac = "00:11:22:EE:ff:aa";
if(filter_var($mac, FILTER_VALIDATE_MAC)) {
	echo $mac." is a valid mac address. <br>";
} else {
	echo $mac." is not valid mac address. <br>";
}

结果：

1.2.3.4 is valid IP 
311.2.3.4 is not valid IP 
10.1.1.1 is not public IPv4 
FF01::101 is valid IPv6 
a@bc.cn is a valid email. 
http://blog.csdn.net/972301/article/details/50654449 is a valid url. 
00:11:22:EE:ff:aa is a valid mac address. 

当然，更详细的解释和filters，还是要看看官网： http://php.net/manual/en/filter.filters.php

编后按

猫哥曰：正则虽好，效率第一，为了进度，你懂的~