C# if-null-then-null expression

Question

Just for curiosity/convenience: C# provides two cool conditional expression features I know of:

string trimmed = (input == null) ? null : input.Trim();
         


        

Answer 1

There's nothing built-in, but you could wrap it all up in an extension method if you wanted (although I probably wouldn't bother).

For this specific example:

string trimmed = input.NullSafeTrim();

// ...

public static class StringExtensions
{
    public static string NullSafeTrim(this string source)
    {
        if (source == null)
            return source;    // or return an empty string if you prefer

        return source.Trim();
    }
}

Or a more general-purpose version:

string trimmed = input.IfNotNull(s => s.Trim());

// ...

public static class YourExtensions
{
    public static TResult IfNotNull(
        this TSource source, Func func)
    {
        if (func == null)
            throw new ArgumentNullException("func");

        if (source == null)
            return source;

        return func(source);
    }
}