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
The != operator serves this purpose for bool values.
foo->bar() is the same as (*foo).bar(). The parenthesizes above are necessary because of the binding strength of the * and . operators. *foo.bar() wouldn’t work because Dot (.) operator is evaluated first (see operator precedence) The Dot (.) operator can’t be overloaded, arrow (->) operator can be overloaded. The Dot (.) operator can’t be applied … Read more
and is the same as && but with lower precedence. They both use short-circuit evaluation. WARNING: and even has lower precedence than = so you’ll usually want to avoid and. An example when and should be used can be found in the Rails Guide under “Avoiding Double Render Errors”.
Just like the & and && operator, the double Operator is a “short-circuit” operator. For example: if(condition1 || condition2 || condition3) If condition1 is true, condition 2 and 3 will NOT be checked. if(condition1 | condition2 | condition3) This will check conditions 2 and 3, even if 1 is already true. As your conditions can … Read more
As others have said, it will only work when T is constrained to be a reference type. Without any constraints, you can compare with null, but only null – and that comparison will always be false for non-nullable value types. Instead of calling Equals, it’s better to use an IComparer<T> – and if you have … Read more
a ||= b is a conditional assignment operator. It means: if a is undefined or falsey, then evaluate b and set a to the result. Otherwise (if a is defined and evaluates to truthy), then b is not evaluated, and no assignment takes place. For example: a ||= nil # => nil a ||= 0 … Read more
I divide the operators, for the purpose of teaching, into four categories: Keywords/reserved symbols Automatically imported methods Common methods Syntactic sugars/composition It is fortunate, then, that most categories are represented in the question: -> // Automatically imported method ||= // Syntactic sugar ++= // Syntactic sugar/composition or common method <= // Common method _._ // … Read more
Use !=. See comparison operators. For comparing object identities, you can use the keyword is and its negation is not. e.g. 1 == 1 # -> True 1 != 1 # -> False [] is [] #-> False (distinct objects) a = b = []; a is b # -> True (same object)
>> is arithmetic shift right, >>> is logical shift right. In an arithmetic shift, the sign bit is extended to preserve the signedness of the number. For example: -2 represented in 8 bits would be 11111110 (because the most significant bit has negative weight). Shifting it right one bit using arithmetic shift would give you … Read more