I want to convert a nullable numeric into a string maintaining the null value. This is what I'm doing:
int? i = null;
string s = i == null ? null : i.ToString();
Is there something shorter?
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Don't think there is anything shorter actuallyGerald Versluis– Gerald Versluis2012-07-13 14:14:57 +00:00Commented Jul 13, 2012 at 14:14
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Other than an extension method, don't see this getting any shorter.NominSim– NominSim2012-07-13 14:17:30 +00:00Commented Jul 13, 2012 at 14:17
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5 Answers
You can write some extension method:
public static string ToNullString(this int? i)
{
return i.HasValue ? i.ToString() : null;
}
Usage will be more simple:
string s = i.ToNullString();
Or generic version:
public static string ToNullString<T>(this Nullable<T> value)
where T : struct
{
if (value == null)
return null;
return value.ToString();
}
answered Jul 13, 2012 at 14:16
Sergey Berezovskiy
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4 Comments
Jordão
I'm sorry about adding a similar answer, it's just that I thought of a more generic version than yours....
psubsee2003
No sense keeping my answer as yours is effectively the same in a much cleaner extension method +1.
Sergey Berezovskiy
@Clodoaldo actually he is not :)
Jordão
OK, I'll +1 you so that I don't feel so bad for being selected... Even if I get unselected that's fine...
You could create an extension method for that:
public static string ToStringOrNull<T>(this Nullable<T> nullable)
where T : struct {
return nullable.HasValue ? nullable.ToString() : null;
}
Usage:
var s = i.ToStringOrNull();
UPDATE
Since C# 6, you can use the much more convenient null-conditional operator:
var s = i?.ToString();
2 Comments
Sergey Berezovskiy
Oops.. This time I'm sorry - just wanted to create more generic version of my answer :) I didn't copy yours!
QMaster
I need formatProvider parameter for decimal type so removed generic version to specialize to decimal extension as my answer in stackoverflow.com/a/47835010/1830909, Unfortunately can't write method in comment and must be written as new answer, do you have any better idea?
I think
string s = i?.ToString();
is shorter.
2 Comments
Jordão
Yes! +1. But you have to appreciate that this question was asked and answered before that operator was available in the language. Nevertheless, I've updated my answer with that as well.
Ceisc
Yeah, was aware that the question predates the availability of the operator. Just thought I'd throw it out there in case it's helpful to anyone.
We can also use System.Convert i.e.
int? i = null;
string s = Convert.ToString(i); // it gives null if i is null.
And as already mentioned we can also use null conditional operator
string s = i?.ToString();
Comments
I need formatProvider parameter for decimal type so removed generic version to specialize to decimal extension as below:
public static string ToStringOrNull(this Nullable<decimal> nullable, string format = null)
{
string resTmp = "";
if (nullable.HasValue)
{
if (format != null)
{
resTmp = nullable.Value.ToString(format);
}
else
{
resTmp = nullable.ToString();
}
}
else
{
resTmp = "";
}
return resTmp;
}
1 Comment
QMaster
@Jordão Yeah, I have some nullable decimal field in my db tables therefor in entity framework model defined as nullable decimal. For using them in web app view, must be convert to string and as nullable type I can't using the standard ToString() method.