function ipToNumber(ip) { 
  var num = 0; 
  if(ip == "") { 
    return num; 
  }   
  var aNum = ip.split(".");  
  if(aNum.length != 4) { 
    return num; 
  }   
  num += parseInt(aNum[0]) << 24; 
  num += parseInt(aNum[1]) << 16; 
  num += parseInt(aNum[2]) << 8; 
  num += parseInt(aNum[3]) << 0; 
  num = num >>> 0;//这个很关键，不然可能会出现负数的情况 
  return num;  
}   
  
function numberToIp(number) {   
  var ip = ""; 
  if(number <= 0) { 
    return ip; 
  } 
  var ip3 = (number << 0 ) >>> 24; 
  var ip2 = (number << 8 ) >>> 24; 
  var ip1 = (number << 16) >>> 24; 
  var ip0 = (number << 24) >>> 24 
   
  ip += ip3 + "." + ip2 + "." + ip1 + "." + ip0; 
   
  return ip;   
} 

//IP转成整型
function _ip2int(ip) 
{
  var num = 0;
  ip = ip.split(".");
  num = Number(ip[0]) * 256 * 256 * 256 + Number(ip[1]) * 256 * 256 + Number(ip[2]) * 256 + Number(ip[3]);
  num = num >>> 0;
  return num;
}
//整型解析为IP地址
function _int2iP(num) 
{
  var str;
  var tt = new Array();
  tt[0] = (num >>> 24) >>> 0;
  tt[1] = ((num << 8) >>> 24) >>> 0;
  tt[2] = (num << 16) >>> 24;
  tt[3] = (num << 24) >>> 24;
  str = String(tt[0]) + "." + String(tt[1]) + "." + String(tt[2]) + "." + String(tt[3]);
  return str;
}