# false && false is false?

3/31/2017 10:13:11 AM

Kelvin Nderitu8 Answers

New Answer--- AND --- false && false: false false && true: false true && false: false true && true: true --- OR --- false || false: false false || true: true true || false: true true || true: true --- NOT --- !false: true !true: false Source: http://stackoverflow.com/questions/7583853/true-and-false-for-logic-and-logic-table

My teacher taught me this some years back. 2 lies (2 falses) make 1 big lie (false) but not a truth.

Let us do little maths and assign 1 to 'true' and 0 to 'false' && (and) operation is equivalent to the product of numbers hence false && false = 0 X 0 = 0 = false. Isn't simple

Just to complete the previous answers: && (there're two &s here) acts as a shortcut operator, meaning that when you type a&&b, "a" is evaluated first, and if it's false, "b" is not evaluated and the whole condition is false. So strictly speaking, false&&false is false because of the first false (the one at the left of &&). https://msdn.microsoft.com/en-us/library/2a723cdk.aspx

AND (&&) -> if any is FALSE then result is FALSE -> therefore, all must be TRUE for result to be TRUE OR (||) -> if any is TRUE then result is TRUE -> all must be FALSE for result to be FALSE NOT (!) -> reverts the value, eg. not FALSE is TRUE and not TRUE is FALSE Priority order of evaluation: NOT, AND, OR eg: -> NOT FALSE || TRUE && FALSE => TRUE -> order of eval. can be changed with "()", eg: -> NOT (FALSE || TRUE) && FALSE => FALSE it makes sense if you think logically, to get TRUE -> with AND, *all* conditions must be TRUE -> but with OR, *any* can be TRUE maybe I'm biased by experience, i don't know, but don't worry about it, soon it will come to you as natural as 1+1. hope it helps