js 匹配IP地址的正则表达式

<script>
ip= "192.157.4.4 "
re=/(d+).(d+).(d+).(d+)/g     //匹配ip地址的正则表达式
alert(re.test(ip))
</script>

<script>
ip= "555.255.284.255 "
re=/^(([3-9]d?|[01]d{0,2}|2d?|2[0-4]d|25[0-5]).){3}([3-9]d?|[01]d{0,2}|2d?|2[0-4]d|25[0-5])/

alert(re.test(ip))
</script>

<script>
var   ip= "61.255.204.259 ";
if(ip.match(/(d+).(d+).(d+).(d+)/g))
      alert( "error   ip   address   format. ");

var   parts=ip.split( ". ");
for(var   i=0,l=parts.length;i <l;i++){
      if(parseint(parts[i],10)> 255){
            alert( "error   ip   address   format. ");
            break;
      }
}