驗證子網掩碼合法性程式碼例項

子網掩碼必須是 1 和 0組成的連續的一段 如 11110000 

程式碼例項如下:

[JavaScript] 純文字檢視 複製程式碼
var judgeSubnetMask = function(ipAddress){
  var binaryIpString = praseIpToBinary(ipAddress).toString();
  var subIndex = binaryIpString.lastIndexOf("1")+1;
  var frontHalf = binaryIpString.substring(0,subIndex);
  var backHalf = binaryIpString.substring(subIndex);
  if(frontHalf.indexOf("0") != -1 || backHalf.indexOf("1") != -1){
    return false;
  }else{
    return true;
  }
}