Boolean implication A implies B simply means “if A is true, then B must be true”. This implies (pun intended) that if A isn’t true, then B can be anything. Thus: False implies False -> True False implies True -> True True implies False -> False True implies True -> True This can also be … Read more
From MSDN: Short-Circuiting Trade-Offs Short-circuiting can improve performance by not evaluating an expression that cannot alter the result of the logical operation. However, if that expression performs additional actions, short-circuiting skips those actions. For example, if the expression includes a call to a Function procedure, that procedure is not called if the expression is short-circuited, … Read more
In the first two cases, the boolean is cast to a number – 1 for true and 0 for false. In the final case, it is a number that is cast to a boolean and any number except for 0 and NaN will cast to true. So your test cases are really more like this: … Read more
It’s an old-ish idiom; inserting parentheses to show priority, (port == “443” and “https://”) or “http://” x and y returns y if x is truish, x if x is falsish; a or b, vice versa, returns a if it’s truish, otherwise b. So if port == “443” is true, this returns the RHS of the … Read more
Here’s another way to think about it. Consider four sets: Blue things, red things, big things, and small things. If you intersect the set of all blue things and all small things, you end up with the union of the properties — everything in the set has both the blue property and the small property. … Read more
Rather than writing: if (someExpression) { return true; } else { return false; } Write: return someExpression; As for the expression itself, something like this: boolean atLeastTwo(boolean a, boolean b, boolean c) { return a ? (b || c) : (b && c); } or this (whichever you find easier to grasp): boolean atLeastTwo(boolean a, … Read more
Here’s another way to think about it. Consider four sets: Blue things, red things, big things, and small things. If you intersect the set of all blue things and all small things, you end up with the union of the properties — everything in the set has both the blue property and the small property. … Read more
From help(“<“): If the two arguments are atomic vectors of different types, one is coerced to the type of the other, the (decreasing) order of precedence being character, complex, numeric, integer, logical and raw. So in this case, the numeric is of lower precedence than the character. So 2 is coerced to the character “2”. … Read more
However, I know some that some compilers will exit the boolean expression entirely if the first condition fails. Is this true with Java? Yes, that is known as Short-Circuit evaluation.Operators like && and || are operators that perform such operations. Or is the order of evaluation not guaranteed? No,the order of evaluation is guaranteed(from left … Read more
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 … Read more