It’s a matter of operator precedence. || has a higher precedence than or. So, in between the two you have other operators including ternary (? 🙂 and assignment (=) so which one you choose can affect the outcome of statements. Here’s a ruby operator precedence table. See this question for another example using and/&&. Also, … Read more
This is a conversion operator. It means that you can write this code: XmlBase myBase = new XmlBase(); XElement myElement = myBase; And the compiler won’t complain! At runtime, the conversion operator will be executed – passing myBase in as the argument, and returning a valid XElement as the result. It’s a way for you … Read more
As if is function in R and returns the latest evaluation, if-else is equivalent to ?:. > a <- 1 > x <- if(a==1) 1 else 2 > x [1] 1 > x <- if(a==2) 1 else 2 > x [1] 2 The power of R is vectorization. The vectorization of the ternary operator is … Read more
Here is how I pronounce them: >>= bind >> then *> then -> to a -> b: a to b <- bind (as it desugars to >>=) <$> (f)map <$ map-replace by 0 <$ f: “f map-replace by 0″ <*> ap(ply) (as it is the same as Control.Monad.ap) $ (none, just as ” ” [whitespace]) … Read more
It’s not the “double not operator”, it’s the not operator applied twice. The right ! will result in a boolean, regardless of the operand. Then the left ! will negate that boolean. This means that for any true value (numbers other than zero, non-empty strings and arrays, etc.) you will get the boolean value TRUE, … Read more
& <– verifies both operands && <– stops evaluating if the first operand evaluates to false since the result will be false (x != 0) & (1/x > 1) <– this means evaluate (x != 0) then evaluate (1/x > 1) then do the &. the problem is that for x=0 this will throw an … Read more
The -Contains operator doesn’t do substring comparisons and the match must be on a complete string and is used to search collections. From the documentation you linked to: -Contains Description: Containment operator. Tells whether a collection of reference values includes a single test value. In the example you provided you’re working with a collection containing … Read more
This is literally called the … operator in PHP, but is known as the splat operator from other languages. From a 2014 LornaJane blog post on the feature: This feature allows you to capture a variable number of arguments to a function, combined with “normal” arguments passed in if you like. It’s easiest to see … Read more
Remember that negative numbers are stored as the two’s complement of the positive counterpart. As an example, here’s the representation of -2 in two’s complement: (8 bits) 1111 1110 The way you get this is by taking the binary representation of a number, taking its complement (inverting all the bits) and adding one. Two starts … Read more
From the documentation: The @ (at) operator is intended to be used for matrix multiplication. No builtin Python types implement this operator. The @ operator was introduced in Python 3.5. @= is matrix multiplication followed by assignment, as you would expect. They map to __matmul__, __rmatmul__ or __imatmul__ similar to how + and += map … Read more