& is bitwise AND This operator expects two numbers and retuns a number. In case they are not numbers, they are cast to numbers. How does it work? Wikipedia has an answer: https://en.wikipedia.org/wiki/Bitwise_operation#AND Note: In Javascript, the usage of this operator is discouraged, since there’s no integer data type, just floating point. Thus floats are … Read more
Those are the bitwise AND and bitwise OR operators. int a = 6; // 110 int b = 4; // 100 // Bitwise AND int c = a & b; // 110 // & 100 // —– // 100 // Bitwise OR int d = a | b; // 110 // | 100 // —– … Read more
All values in JavaScript are either “truthy” or “falsy”. a && b evaluates to the first falsy operand, a || b evaluates to the first truthy operand. Both operators will not evaluate any operands after the one the return. If all operands don’t match, they will evaluate to the last one. !a evaluates to true … Read more
The statement (4 > y > 1) is parsed as this: ((4 > y) > 1) The comparison operators < and > evaluate left-to-right. The 4 > y returns either 0 or 1 depending on if it’s true or not. Then the result is compared to 1. In this case, since 0 or 1 is … Read more
The and and or operators do return one of their operands, not a pure boolean value like True or False: >>> 0 or 42 42 >>> 0 and 42 0 Whereas not always returns a pure boolean value: >>> not 0 True >>> not 42 False
In JavaScript, both || and && are logical short-circuit operators that return the first fully-determined “logical value” when evaluated from left to right. In expression X || Y, X is first evaluated, and interpreted as a boolean value. If this boolean value is “true”, then it is returned. And Y is not evaluated. (Because it … Read more
Basically, the Logical AND operator (&&), will return the value of the second operand if the first is truthy, and it will return the value of the first operand if it is by itself falsy, for example: true && “foo”; // “foo” NaN && “anything”; // NaN 0 && “anything”; // 0 Note that falsy … Read more
And has precedence over Or, so, even if a <=> a1 Or a2 Where a And b is not the same as Where a1 Or a2 And b, because that would be Executed as Where a1 Or (a2 And b) and what you want, to make them the same, is the following (using parentheses to … Read more
The shorter ones are vectorized, meaning they can return a vector, like this: ((-2:2) >= 0) & ((-2:2) <= 0) # [1] FALSE FALSE TRUE FALSE FALSE The longer form evaluates left to right examining only the first element of each vector, so the above gives ((-2:2) >= 0) && ((-2:2) <= 0) # [1] … Read more
TL;DR We start by summarising the two behaviour of the two logical operators and and or. These idioms will form the basis of our discussion below. and Return the first Falsy value if there are any, else return the last value in the expression. or Return the first Truthy value if there are any, else … Read more