boolean-operations

Is it really a good practice to avoid using NOT operator in IF conditions in order to make your code better readable? I heard the if (doSomething()) is better then if (!doSomething()). It really depends on what you're trying to accomplish. If you have no else clause then if(!doSomething()) seems fine. However, if you have if(!doSomething()) { ... } else { // do something else } I'd probably reverse that logic to remove the ! operator and make the if clause slightly more clear. hvgotcodes As a general statement, its good to make your if conditionals as readable as possible. For your example,

Trying to perform a single boolean NOT operation, it appears that under MS SQL Server 2005, the following block does not work DECLARE @MyBoolean bit; SET @MyBoolean = 0; SET @MyBoolean = NOT @MyBoolean; SELECT @MyBoolean; Instead, I am getting more successful with DECLARE @MyBoolean bit; SET @MyBoolean = 0; SET @MyBoolean = 1 - @MyBoolean; SELECT @MyBoolean; Yet, this looks a bit a twisted way to express something as simple as a negation. Am I missing something? Use the ~ operator: DECLARE @MyBoolean bit SET @MyBoolean = 0 SET @MyBoolean = ~@MyBoolean SELECT @MyBoolean Your solution is a good

In natural languages, we would say "some color is a primary color if the color is red, blue, or yellow." In every programming language I've seen, that translates into something like: isPrimaryColor = someColor == "Red" or someColor == "Blue" or someColor == "Yellow" Why isn't there a syntax that more closely matches the English sentence. After all, you wouldn't say "some color is a primary color if that color is red, or that color is blue, or that color is yellow." I realize simply isPrimaryColor = someColor == ("Red" or "Blue" or "Yellow") because instead of Red Blue and Yellow they could be

Is there a "very bad thing" that can happen &&= and ||= were used as syntactic sugar for bool foo = foo && bar and bool foo = foo || bar ? A bool may only be true or false in C++. As such, using &= and |= is relatively safe (even though I don’t particularly like the notation). True, they will perform bit operations rather than logical operations (and thus they won’t short-circuit) but these bit operations follow a well-defined mapping, which is effectively equivalent to the logical operations, as long as both operands are of type bool . 1 Contrary to what other people have said here, a bool in

I found a really good example about boolean translator, * Boolean expression (grammar) parser in c++ What I am thinking now is to do a further step, translate (!T|F)&T into F or 0 , so it is very convenient for calculating a very long boolean expression. Is there some examples about this using spirit? What I have done is making a calculator first, and then let it calculate '(T+!F*T)', which equal to (T||!F&&T) but when I type () , there is an error. How to modify it? Thanks a lot! #include <iostream> #include <stack> #include <boost/lexical_cast.hpp> #include <boost/config/warning_disable.hpp>

I would like the element-wise logical OR operator. I know "or" itself is not what I am looking for. I am aware that AND corresponds to & and NOT, ~ . But what about OR? deinonychusaur The corresponding operator is | : df[(df < 3) | (df == 5)] would elementwise check if value is less than 3 or equal to 5. If you need a function to do this, we have np.logical_or . For two conditions, you can use df[np.logical_or(df<3, df==5)] Or, for multiple conditions use the logical_or.reduce , df[np.logical_or.reduce([df<3, df==5])] Since the conditions are specified as individual arguments, parentheses

Could you please explain the deMorgan rules as simply as possible (e.g. to someone with only a secondary school mathematics background) ? We have two values: T and F . We can combine these values in three ways: NOT , AND , and OR . NOT is the simplest: NOT T = F NOT F = T We can write this as a truth table : when given.. | results in... ============================ T | F F | T For conciseness x | NOT x ========= T | F F | T Think of NOT as the complement , that is, it turns one value into the other. AND works on two values: x y | x AND y ============= T T | T T F | F F T | F F F | F AND is T