ternary operator without else in C

Question

I want to use ternary operator without else in C. How do I do it.

(a)? b: nothing; 

something like this. What do I use in nothing part?

Answer 1

If you are using a ternary operator like that, presumably it could be replaced by:

if (a) { b; } 

which is much, much better. (The intent is clearer, so the code is easier to read, and there will be no performance loss.)

However, if you are using the ternary operator as an expression, i.e.

printf("%d cat%s", number_of_cats, number_of_cats != 1 ? "s" : <nothing>);  a = b*c + (d == 0 ? 1 : <nothing>); 

then the <nothing> value depends on the context it is being used in. In my first example, <nothing> should be "", and in the second it should be 0.

Answer 2

An omitted false expression is invalid. Try reversing the condition instead.

(!a) ?: b;