conditional statement with ||

Say I have

If A && B && C
  ...do something if A = B = C = true
end

Is it faster, however to do:

If ~(A || B || C)
 ..do something if A or B or C = false
end

I am wondering if the latter statement is faster because it should be able break if any of the conditions are false and not test the rest. But I am wondering if the negation forces all of the conditions to be tested first?

Answer 1

[Fangjun Jiang]

If A is false, then A && B will be short-circuited. No need to use the latter approach. Use the first one because it's easy to read.

Answer 2

[Walter Roberson]

The two expressions are not equivalent.

A && B && C

is true only if A and B and C are all true.

~(A||B||C)

is true only if A and B and C are all false, not if one of them is false.

The logical or equivalent of A && B && C is

~(~A || ~B || ~C)

[Fangjun Jiang]

+1, that's another sharp catch!