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
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
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
Think of ! (negation operator) as “not”, || (boolean-or operator) as “or” and && (boolean-and operator) as “and”. See Operators and Operator Precedence. Thus: if(!(a || b)) { // means neither a nor b } However, using De Morgan’s Law, it could be written as: if(!a && !b) { // is not a and is … Read more
To invert a boolean Series, use ~s: In [7]: s = pd.Series([True, True, False, True]) In [8]: ~s Out[8]: 0 False 1 False 2 True 3 False dtype: bool Using Python2.7, NumPy 1.8.0, Pandas 0.13.1: In [119]: s = pd.Series([True, True, False, True]*10000) In [10]: %timeit np.invert(s) 10000 loops, best of 3: 91.8 µs per … Read more
Order of operations causes (0 < 5 < 3) to be interpreted in javascript as ((0 < 5) < 3) which produces (true < 3) and true is counted as 1, causing it to return true. This is also why (0 < 5 < 1) returns false, (0 < 5) returns true, which is interpreted … Read more