Java ternary operator with empty clause

Question

This question is more for my curiosity than anything else.

I often employ Java's ternary operator to write shorter code. I have been wondering, however, whether it is possible to use it if one of the if or else conditions are empty. In more details:

int x = some_function();
if (x > 0)
    x--;
else
    x++;

can be written as x = (x > 0) ? x-1 : x+1;

But is it possible to write if (x > 0) x-1; as a ternary expression with an empty else clause?

Nitpick: Shouldn't x = (x > 0) ? x-- : x++; be x = (x > 0) ? --x : ++x;? Or even better: x = (x > 0) ? x - 1 : x + 1; — helpermethod
– helpermethod, Commented Oct 30, 2013 at 15:52
Aaack. Please don't write code that assigns to a variable and uses a post-increment or pre-increment on the same variable. It gives me a headache. — ajb
– ajb, Commented Oct 30, 2013 at 16:14

T.J. Crowder · Accepted Answer · 2013-10-30 16:23:03Z

15

But is it possible to write if (x > 0) x--; as a ternary expression with an empty else clause?

No, the conditional operator requires three operands. If you wanted, you could do this:

x = (x > 0) ? x - 1 : x;

...but (subjectively) I think clarity suffers.

edited Oct 30, 2013 at 16:23

answered Oct 30, 2013 at 15:51

T.J. Crowder

1.1m201 gold badges2k silver badges2k bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Plasmarob Over a year ago

I see countless x=x assignments taking place in some place. seems kinda silly and inefficient if that can happen.

Chthonic Project Over a year ago

I agree, clarity certainly suffers. I was curious about Java's take on it since in C (using GCC compiler), one may write something like x = (x>0) ?: x+1;

T.J. Crowder Over a year ago

@ChthonicProject: Interesting, apparently that's a GNU-specific extension. I did check the JLS earlier; didn't see anything saying either of the second and third operands is optional (in Java).

Chthonic Project Over a year ago

Thanks for the link. I didn't know it was GNU-specific, and would have tried it on other platforms too ... and suffered! This was a big help (hence the upvote).

Collectives™ on Stack Overflow

Java ternary operator with empty clause

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related