Unusual use of the Ternary Operator

Question

I'm a newbie to C, I understand why ternary operators can be useful, less code than if/else blocks.

I have been given some C code to maintain, and one thing I've noticed is the previous programmer used ternary operators like this

myInt = (!myInt) ? MACRO1 : MACRO2;

Does this accomplish exactly the same thing as this:

myInt = myInt ? MACRO2 : MACRO1;

Is this just a style thing? Perhaps it makes sense to think "if not" myInt, instead of "if"?

They are exactly the same. However, if the original variable name is better, then leave it alone. — nhahtdh, Aug 10 '12 at 20:11
Its primary usfulness is not "less code", but rather that it is an operator rather than a construct, so can be used anywhere an expression is valid, including function arguments. — Clifford, Aug 10 '12 at 21:57
@nhahtdh what do you mean "if the original variable name is better"? — Doug Molineux, Aug 13 '12 at 14:46
@PeteHerbertPenito: For example, if the original variable name doesn't contain negative word (e.g. `hasProperty`, `isProperty`, as opposed to `isNotProperty`), then using logical NOT operator seems to make more sense. — nhahtdh, Aug 13 '12 at 14:52
Ah I see what you mean, great point, thanks for the response — Doug Molineux, Aug 13 '12 at 17:13

score 6 · Accepted Answer · answered Aug 10 '12 at 20:11

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Yes, this code accomplishes exactly the same thing. It just depends on the logic used when writing the condition - so it can be chalked up to style (i.e. whichever is easier for you to think).

answered Aug 10 '12 at 20:11

RageD

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Ed S. · Answer 2 · 2012-08-10T20:21:04.403

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Yes, you are correct. It seems as though the originator of that code wanted to make the expression slightly more confusing than it needed to be.

edited Aug 10 '12 at 20:21

answered Aug 10 '12 at 20:11

Ed S.

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I agree, the weird thing is he / she consistently used it, sorry I had to mark the other answer as correct, just since he was first. :( thnx for the response tho – Doug Molineux Aug 10 '12 at 20:22

score 2 · Answer 3 · answered Aug 10 '12 at 20:19

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I prefer the second example as it is not using reverse logic, therefore easier to understand and less clutter.

myInt = myInt ? MACRO2 : MACRO1;

answered Aug 10 '12 at 20:19

M3NTA7

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Unusual use of the Ternary Operator

3 Answers3