Write it better/neat/fast (if condition)

Question

How to write following if condition clean/fast/readable. Any one of the fields 'address', 'city', 'district', 'province' can be null. I want to make full address by concat all these fields. Like

address = "Street # 32"
city = "My City"
District = "New York"
Province = "NY"

fullAddress = "Stree #32, My City, New York, NY"

If any information is missing then don't add this in string like if district is missing then don't include it.

address = "Street # 32"
city = "My City"
District = ""
Province = "NY"

fullAddress = "Stree #32, My City, NY"

Following code I have written but not good.

string address = dr["Address"].ToString();
string city = dr["City"].ToString();
string district = dr["District"].ToString();
string province = dr["Province"].ToString();
string fullAddress = "";

if (!string.IsNullOrEmpty(address) && !string.IsNullOrEmpty(city) && !string.IsNullOrEmpty(district) && !string.IsNullOrEmpty(province))
{
    fullAddress = address + ", " + city + ", " + district + ", " + province;
}
else if (!string.IsNullOrEmpty(address) && !string.IsNullOrEmpty(city) && !string.IsNullOrEmpty(district))
{
    fullAddress = address + ", " + city + ", " + district;
}
else if (!string.IsNullOrEmpty(address) && !string.IsNullOrEmpty(city) && !string.IsNullOrEmpty(province))
{
    fullAddress = address + ", " + city + ", " + province;
}
else if (!string.IsNullOrEmpty(address) && !string.IsNullOrEmpty(district) && !string.IsNullOrEmpty(province))
{
    fullAddress = address + ", " + district + ", " + province;
}
else if (!string.IsNullOrEmpty(city) && !string.IsNullOrEmpty(district) && !string.IsNullOrEmpty(province))
{
    fullAddress = city + ", " + district + ", " + province;
}
else if (!string.IsNullOrEmpty(address) && !string.IsNullOrEmpty(city))
{
    fullAddress = address + ", " + city;
}
else if (!string.IsNullOrEmpty(address) && !string.IsNullOrEmpty(province))
{
    fullAddress = address + ", " + province;
}
else if (!string.IsNullOrEmpty(address))
{
    fullAddress = address;
}
else if (!string.IsNullOrEmpty(city))
{
    fullAddress = city;
}

Answer 1

I think using LINQ together with string.Join() would be the best option here:

var fields = new[] { "Address", "City", "District", "Province" };
var setValues = fields.Select(field => (string)dr[field])
                      .Where(value => !string.IsNullOrEmpty(value));
string fullAddress = string.Join(", ", setValues);

Answer 2

I'd suggest to create a method like:

public static string CreateAddressFrom(Dictionary dr)
{
   var addressDetails = new List<string>{"Address","City","District","Province"};
   var fullAddress = string.Empty;

   foreach (var addressDetail in addressDetails)
   {
       string addressDetailStr = dr[addressDetail];
       if (!string.IsNullOrEmpty(addressDetailStr))
           fullAddress += fullAddress + ", " + addressDetailStr;
   }

   return fullAddress.TrimStart(", ".ToCharArray());
}

So your client code now can generate the address like this:

...
var myDictionary = ...;
var fullAddress = CreateAddrressFrom(myDictionary);
...

Hope this helps.

Answer 3

I know there's already an accpeted answer here. But I have another solution, a bit different.

Dictionary<string, string> dr = GetValues(); 
//GetValues is where you would get the data

string addressFromDictionary = dr.Where(k => !String.IsNullOrEmpty(k.Value))
                                 .Select(d => d.Value)
                                 .Aggregate((c, n) => c + ", " + n);

svick's solution works fine. But I would avoid using a separate list with the field-keys. And using the Select() before the Where() first gets all fields from the dictionary and then selects the non-empty ones. Here you only get the fields that have a non-null value and concatenate those values using the Aggregate() function.

Not saying my code is better, just showing another possibility! ;)