Turn this if-then logic into a boolean expression?

Question

I'm having a bit of a brain fart on making this code more concise(preferably a single boolean expression)

This is my code:

                    if (d.Unemployed)
                    {
                        if (type.Unemployed)
                        {
                            tmp.Unemployed = true;
                        }
                        else
                        {
                            tmp.Unemployed = false;
                        }
                    }
                    else
                    {
                        if (type.Unemployed)
                        {
                            tmp.Unemployed = false;
                        }
                        else
                        {
                            tmp.Unemployed = true;
                        }
                    }

Basically the point is that if either type or d is not unemployed, then tmp should be set to not unemployed.

Do you mean “`type` or `d` is not unemployed, *but not both* ”? — svick, Jul 11 '11 at 22:37
@svick: Yes, that's confirmed by the if-else logic in the code. — Justin ᚅᚔᚈᚄᚒᚔ, Jul 11 '11 at 22:41
@Justin, that's why I asked. Your code says something else than your text, or at least it's not clear they mean the same thing. — svick, Jul 11 '11 at 22:44

score 14 · Accepted Answer · answered Jul 11 '11 at 22:36

14

How about:

tmp.Unemployed = type.Unemployed == d.Unemployed;

answered Jul 11 '11 at 22:36

MRAB

20,356
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Ah, now it's obvious that I think about it. Just needed another pair of eyes I guess – Earlz Jul 11 '11 at 22:39

score 8 · Answer 2 · answered Jul 11 '11 at 23:19

If we construct a truth table by following the code, we get

d  | type | tmp
---+------+----
1  |   1  |  1
---+------+----
1  |   0  |  0
----+-----+----
0  |   1  |  0
----+-----+----
0  |   0  |  1

The above is equivalent with the negation of the xor operation.

tmp = not (d xor type)

If the language doesn't have the xor operator we can use the != on boolean values.

tmp = ! (d != type);
// or
tmp = d == type;

score 2 · Answer 3 · answered Jul 11 '11 at 22:44

Thinking about how much "brain fart" this caused you I would consider using a well named variable to avoid having to go through this mental process again in future. Something like this:

isTmpUnemployed = (type.Unemployed == d.Unemployed);
tmp.Unemployed = isTmpUnemployed;

Shaz · Answer 4 · 2011-07-11T22:53:35.037

0

tmp.Unemployed = d.Unemployed || type.Unemployed ? !tmp.Unemployed : null;

edited Jul 11 '11 at 22:53

answered Jul 11 '11 at 22:36

Shaz

15,637
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score 0 · Answer 5 · answered Jul 11 '11 at 22:39

0

The above code means "both unemployed or both not unemployed". Thus, not (A xor B):

 tmp.Unemployed = ! ( D.Unemployed ^ type.Unemployed)

answered Jul 11 '11 at 22:39

Peter O.

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Turn this if-then logic into a boolean expression?

5 Answers5

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