Setting a boolean value based on an integer

Question

I found this statement is some old code and it took me a second to figure out...

IsTestActive = (TestStateID == 1 ? true : false);

Please correct me if I'm wrong but isn't this the same as this one?:

IsTestActive = (TestStateID == 1);

If it is, why would you ever want to use the first? Which one is more readable? (I think the latter, but I'd like to see what others think.)

score 32 · Accepted Answer · answered Jan 07 '09 at 14:04

32

Yes, it is exactly the same.

Yes, the latter is more readable.

answered Jan 07 '09 at 14:04

j_random_hacker

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I've only seen the former used by 2 types of people: those who lack a fundamental understanding of boolean logic, or those that think the ternary operator is really cool. – John Kraft Jan 07 '09 at 16:46
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The former would theoretically have a minute perf hit, though if you're caring about that level of performance then I suspect you have bigger problems... – Dan Puzey Jun 04 '10 at 10:15

score 5 · Answer 2 · answered Jan 07 '09 at 15:11

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IsTestActive = (TestStateID == 1);

is definitely more readable.

You could make a case for defining a constant

ACTIVE = 1

then replacing the boolean variable IsTestActive with

(TestStateID == ACTIVE)

The way the code is now, the state of the boolean IsTestActive will be erroneous if the state of TestStateID changes without updating the boolean. Bypassing the boolean and testing the real source of the information you're after will remove the possibility of this error.

answered Jan 07 '09 at 15:11

Bill the Lizard

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good point, I hate magic integers - but I assume the OP was just posting example code – annakata Jan 07 '09 at 16:36
That may be, but I do see a lot of people using temp variables like this in production code. – Bill the Lizard Jan 08 '09 at 17:45

score 1 · Answer 3 · answered Jan 07 '09 at 14:06

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No, there's no practical reason for using the first version, world isn't perfect, and neither are programmers.

answered Jan 07 '09 at 14:06

arul

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score 0 · Answer 4 · answered Jun 04 '10 at 09:46

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Well, I don't know about other languages, but in PHP it's even more easy, using type-casting:

$IsTestActive = (boolean)$TestStateId;

answered Jun 04 '10 at 09:46

faileN

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score 0 · Answer 5 · answered Jan 07 '09 at 16:31

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Readability depends on where you use this construct. I often find something like

(TestStateID == 1 ? true : false)

Setting a boolean value based on an integer

5 Answers5