Is there a way to use ? : notation without assignment / with methods returning void

Question

Is there a way to use ? : notation in c# without assigning result of the expression, or even with expressions, after ? operator, which do not return any values.

E.g. I want to run something like it

(1=1) ? errorProvider.SetError(control,"Message") : DoNothing();

expression? DoSomething (): DoSomethingElese()

where DoSomething and DoSomethingElse returns types are void.

Why? You can always use `if (expression) DoSomething(); else DoSomethingElese();`. — Henrik, Jun 25 '13 at 10:12
Yes however I was wandering whether there is some way to hack it. — Darqer, Jun 25 '13 at 10:14

score 4 · Accepted Answer · answered Jun 25 '13 at 10:13

No.

?: returns a value based upon a boolean condition. You can't use void in the expression.

Just use if

   if (expression) {
        DoSomething();
   } else {
        DoSomethingElse();
   }

http://msdn.microsoft.com/en-us/library/ty67wk28(v=vs.110).aspx

score 3 · Answer 2 · answered Jun 25 '13 at 10:12

3

No. The whole point of the ternary operator is that it returns something. In other words: the expression must have a return type (other than void). In this case, you just need to use an if/else construction.

answered Jun 25 '13 at 10:12

Pieter van Ginkel

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score 2 · Answer 3 · answered Jun 25 '13 at 10:34

Closest you can get is by extending the boolean type:

public static void IIF(this bool condition, Action doWhenTrue, Action doWhenFalse)
{
    if (condition)
        doWhenTrue();
    else
        doWhenFalse();
}

Then you win a oneliner:

(1 == 1).IIF(() => DoSomething(), () => DoSomethingElse());

score 1 · Answer 4 · answered Jun 25 '13 at 10:18

1

As others have said, you can't - an If/Else would be the right choice. In your example though, you could do something like:

errorProvider.SetError(control, SomeCondition ? "Message" : string.Empty)

answered Jun 25 '13 at 10:18

NDJ

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Is there a way to use ? : notation without assignment / with methods returning void

4 Answers4