怎么利用js正则表达式判断ip地址的合法性（附源码）var reg = /^(\d{1,2}|1\d\d|2[0-4]\

话不多说，直接上源码

<html>
<head>
</head>
 
<body>
<input id="xxx" οnblur="fun();" />
 
<script>
function isValidIP(ip)   
{   
    var reg =  /^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$/   
    return reg.test(ip);   
}  
 
 
function fun()
{
	var ip = document.all.xxx.value;
	if(isValidIP(ip))
	{
		alert("合法");
	}
	else
	{
		alert("不合法");
	}
}
 
</script>
 
</body>
 
</html>