Method call if not null in C#

Question

Is it possible to somehow shorten this statement?

if (obj != null)
    obj.SomeMethod();

because I happen to write this a lot and it gets p

Answer 1

A quick extension method:

    public static void IfNotNull<T>(this T obj, Action<T> action, Action actionIfNull = null) where T : class {
        if(obj != null) {
            action(obj);
        } else if ( actionIfNull != null ) {
            actionIfNull();
        }
    }

example:

  string str = null;
  str.IfNotNull(s => Console.Write(s.Length));
  str.IfNotNull(s => Console.Write(s.Length), () => Console.Write("null"));

or alternatively:

    public static TR IfNotNull<T, TR>(this T obj, Func<T, TR> func, Func<TR> ifNull = null) where T : class {
        return obj != null ? func(obj) : (ifNull != null ? ifNull() : default(TR));
    }

example:

    string str = null;
    Console.Write(str.IfNotNull(s => s.Length.ToString());
    Console.Write(str.IfNotNull(s => s.Length.ToString(), () =>  "null"));

Answer 2

Yes, in C# 6.0 -- https://msdn.microsoft.com/en-us/magazine/dn802602.aspx.

object?.SomeMethod()

Answer 3

I agree with the answer by Kenny Eliasson. Go with Extension methods. Here is a brief overview of extension methods and your required IfNotNull method.

Extension Methods ( IfNotNull method )

Answer 4

There is a little-known null operator in C# for this, ??. May be helpful:

http://weblogs.asp.net/scottgu/archive/2007/09/20/the-new-c-null-coalescing-operator-and-using-it-with-linq.aspx

Answer 5

I have made this generic extension that I use.

public static class ObjectExtensions {
    public static void With<T>(this T value, Action<T> todo) {
        if (value != null) todo(value);
    }
}

Then I use it like below.

string myString = null;
myString.With((value) => Console.WriteLine(value)); // writes nothing
myString = "my value";
myString.With((value) => Console.WriteLine(value)); // Writes `my value`