分析12位數字的識別號碼

Question

我必須分析12位數字。所以我被卡在7號和8號之間。如果數字是40（第7位是4，數字8是0）給我「ex.London」，如果它是45給我「ex.NY」，我想要的是...

代碼：

[WebMethod] 
    public string ID(string number) 
    { 
     int fullInt = Int32.Parse(number); 
     string City1= number.Substring(0, 2); 
     string City1_S = "Date of birth: " + City1; 

     string City2 = number.Substring(2,2); 
     string City2_S = "Month: " + City2; 

     string City3 = number.Substring(4, 3); 
     string City3_S = "Year: 1" + City3; 

     string City4 = number.Substring(7, 2).Contains("40").ToString(); 
     string City4_S = "City: London"; 

     string[] Array= new string[3]; 
     Array[0] = City1_S.ToString(); 
     Array[1] = City2_S.ToString(); 
     Array[2] = City3_S.ToString(); 
     Array[3] = City4_S.ToString(); 

     return Array.ToString(); 
    } 

Answer 1

[WebMethod] 
public string ID(string number) 
{ 
    int fullInt = Int32.Parse(number);// if (Regex.IsMatch(number, @"\D")) throw new ArgumentException(); 
    string City1_S = "Date of birth: " + number.Substring(0, 2); 
    string City2_S = "Month: " + number.Substring(2,2); 
    string City3_S = "Year: 1" + number.Substring(4, 3); 

    string City4_S = ""; 
    var digitStr = number.Substring(7, 2); 
    switch (digitStr) 
    { 
     case "40": 
      City4_S = "City: London"; 
      break; 
     case "45": 
      City4_S = "City: NY"; 
      break; 
    } 

    string[] Array = new [] { City1_S, City2_S, City3_S, City4_S }; 

    return Array.ToString();//something wrong =) 
    //return string.Join(" ", Array); 
    //return Array[0] + " " + Array[1] + " " + Array[2] + " " + Array[3]; 
}