syntax - What does %>% function mean in R? - Stack Overflow
2014年11月25日 · The funny percent-sign syntax is how R lets users define their own infix functions. An example of a built-in infix operator in R is +; the + in 1 + 2 actually does the function call `+`(1, 2) (you can see this by looking at the source code by typing in `+`).
How do function pointers in C work? - Stack Overflow
2009年5月8日 · Function pointers become easy to declare once you have the basic declarators: id: ID: ID is a; Pointer: *D: D pointer to; Function: D(<parameters>): D function taking <parameters> returning; While D is another declarator built using those same rules. In the end, somewhere, it ends with ID (see below for an example), which is the name of the ...
What's the difference between a method and a function?
2008年9月30日 · Function is a code that has to play a role (a function) of doing something. Method is a method to resolve the problem. It does the same thing. It is the same thing. If you want to be super precise and go along with the convention …
language agnostic - What is a callback function? - Stack Overflow
2009年5月5日 · A callback function is a function you pass (as a reference or a pointer) to a certain function or object. This function or object will call this function back any time later, possibly multiple times, for any kind of purpose : notifying the end of a task; requesting comparison between two item (like in c qsort()) reporting progress of a process
Passing functions with arguments to another function in Python?
# generic function takes op and its argument def runOp(op, val): return op(val) # declare full function def add(x, y): return x+y # run example def main(): f = lambda y: add(3, y) result = runOp(f, 1) # is 4 Create Your Own Wrapper. Here you need to create a …
How can I return two values from a function in Python?
Values aren't returned "in variables"; that's not how Python works. A function returns values (objects). A variable is just a name for a value in a given context. When you call a function and assign the return value somewhere, what you're doing is giving the received value a …
What is the purpose of std::function and how do I use it?
2023年9月22日 · std::function. This is a declaration for a function taking no parameters, and returning no value. If the function returned an int, it would look like this: std::function<int()> Likewise, if it took an int parameter as well: std::function<int(int)> I suspect your main confusion is the next part. []() { FNAME(); }; The [] part is called a capture ...
Function vs. Stored Procedure in SQL Server - Stack Overflow
2023年1月9日 · Function must return a value but in Stored Procedure it is optional( Procedure can return zero or n values). Functions can have only input parameters for it whereas Procedures can have input/output parameters . Function takes one input parameter it is mandatory but Stored Procedure may take o to n input parameters..
What does -> mean in Python function definitions? - Stack Overflow
2013年1月17日 · PEP 3107 -- Function Annotations described the specification, defining the grammar changes, the existence of func.__annotations__ in which they are stored and, the fact that it's use case is still open. In Python 3.5 though, PEP 484 -- Type Hints attaches a single meaning to this: -> is used to
Check if a variable is of function type - Stack Overflow
I think you can just define a flag on the Function prototype and check if the instance you want to test inherited that. define a flag: Function.prototype.isFunction = true; and then check if it exist. var foo = function(){}; foo.isFunction; // will return true