The object i is from database. PrDT is a string, PrDateTime is DataTimeOffset type, nullable
vi.PrDT = i.PrDateTime.Value.ToString("s");
What is the quick way? I don't want if else etc...
5 Answers
Using the conditional operator:
vi.PrDT = i.PrDateTime.HasValue ? i.PrDateTime.Value.ToString("s") :
string.Empty;
11 Comments
KeithS
@MichaelPaulukonis - Pretty much.
Esailija
No, if else are both blocks and this is an expression
Matthew Cox
@Oded "What happens if PrDateTime is null?" The same question applies to your code right now as well
KeithS
@Esailija - an if/else can be constructed without braces, and the IL that would be generated between the two is so similar tas to be considered identical.
Oded
@MatthewCox - No, it doesn't.
PrDateTime is a DateTime? - HasValue will either be true or false. |
You can do an extensions method:
public static class NullableToStringExtensions
{
public static string ToString<T>(this T? value, string format, string coalesce = null)
where T : struct, IFormattable
{
if (value == null)
{
return coalesce;
}
else
{
return value.Value.ToString(format, null);
}
}
}
and then:
vi.PrDT = i.PrDateTime.ToString("s", string.Empty);
1 Comment
Michael Paulukonis
There's an if..else in there, but this seems to be the fastest way (reusable) to do it.
string.Format("{0:s}", i.PrDateTime)
The above will return back an empty string if it's null. Since Nullable<T>.ToString checks for a null value and returns an empty string if it is, otherwise returns a string representation (but can't use formatting specifiers). Trick is to use string.Format, which allows you to use the format specifier you want (in this case, s) and still get the Nullable<T>.ToString behavior.
Comments
return (i.PrDateTime.Value ?? string.Empty).ToString();
Just tested and it seems to work.
Comments
return i.PrDateTime.Value.ToString("s") ?? string.Empty;
1 Comment
Stan R.
to be clear it fails if
i.PrDateTime.Value is null, not i.PrDataTime, but I don't even understand this syntax...how can ToString("s") ever return a null..