When should I apply demorgans law in programming? -

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i think programmer has taken intro programming class had memorize demorgan's law.

in case don't know is, here gist

!(a && b) = !a || !b
!(a || b) = !a && !b

i under assumption if had memorize it, find applicable in programming situation. haven't had use @ all.

is there reason why should use in programming? make program faster, or make conditions easier read?

keeping code readable big reason, , i'm sure whoever works on code after agree it's important one. , you'll save cpu cycle or 2 if invert (!) 1 value instead of two.

another reason bypass short-circuiting. when many languages see !a || !b stop evaluating if !a true because doesn't matter if !b true or not. !a enough or true.

if , b functions instead of variables, , want both execute, you're gonna have problem:

if( !save_record() || !save_another_record() ) { echo 'something bad happened'; }

demorgan's laws let replace or and. both sides of , need evaluated make sure it's true:

if( !( save_record() && save_another_record() ) ) { echo 'something bad happened'; }


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