Javascript实现PHP的ip2long() 和 long2ip()

            function ipToNumber(ip) {    
                var ips = 0, numbers = ip.split(".");

//              return parseInt(numbers[0])*256*256*256 +     
//              parseInt(numbers[1])*256*256 +     
//              parseInt(numbers[2])*256 +     
//              parseInt(numbers[3]);

                //等价上面
                for (var i = 0; i < 4; ++i) {
                    ips = ips << 8 | parseInt(numbers[i]);
                }
                return ips;   
            }    

            function numberToIp(number) {    
//              return (Math.floor(number/(256*256*256))) + "." +     
//              (Math.floor(number%(256*256*256)/(256*256))) + "." +     
//              (Math.floor(number%(256*256)/256)) + "." +     
//              (Math.floor(number%256));

                //等价上面
                var ip = [];
                for (var i = 3; i >= 0; i--) {
                    ip[i] = number & 0xff;
                    number = number >> 8;
                }

                return ip.join(".");                
            }