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Re^2: Multiple numeric not or compare in if statement

by perlfan (Priest)
 on Jul 02, 2020 at 05:32 UTC Need Help??

OP: maybe it was an oversight, but when changing the nested logic in a condition such as that you must necessarily change the higher level logic if you wish for the original to be equivalent exactly opposite to the negated version.

```if ((\$a == 3) || (\$a ==  77) || (\$a == 8))
-- is exactly opposite to --
if ((\$a != 3) && (\$a !=  77) && (\$a != 8))

Update: correct - meant to show exact opposites, used the most wrong possible to describe this.

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Re^3: Multiple numeric not or compare in if statement
by haukex (Bishop) on Jul 02, 2020 at 07:44 UTC
```if ((\$a == 3) || (\$a ==  77) || (\$a == 8))
-- is equivalent to --
if ((\$a != 3) && (\$a !=  77) && (\$a != 8))

No, those two aren't equivalent, they're exact opposites. It seems you didn't apply what you said:

when changing the nested logic in a condition such as that you must necessarily change the higher level logic if you wish for the original to be equivalent to the negated version.
```if ((\$a == 3) || (\$a ==  77) || (\$a == 8))
-- is equivalent to --
if (!( (\$a != 3) && (\$a !=  77) && (\$a != 8) ))
Thanks, updated. Meant to show the exact opposite; said the opposite thing instead.
Re^3: Multiple numeric not or compare in if statement
by BillKSmith (Prior) on Jul 02, 2020 at 15:33 UTC

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