methods

问题 I am confused about how parametric methods work in Julia. I also hope that parametric is the right word to use here. I've read the docs on methods but it is still not clear why the following error occurs. If I define a function as below function Bazinga{T<:Real}(mat ::Union{Array{T,2},SparseMatrixCSC}) mat^4 end and run Penny = sparse(randn(10,10)) Bazinga(Penny) I get ERROR: MethodError: `Bazinga` has no method matching Bazinga(::SparseMatrixCSC{Float64,Int64}) Closest candidates are:

问题 I am doing a code review on some large class libraries and I was wondering if anyone knows of an easy easy way to generate a list of all the methods (and possibly properties/variables too) and their access modifiers. For example, I would like something like this: private MyClass.Method1() internal MyClass.Method2() public MyOtherClass.Method1() Something kind of like a C++ header file, but for C#. This would put everything in one place for quick review, then we can investigate whether some

问题 public class Test { public static void main(String args[]){ Test t = new Test(); t.inner(); } public final void print() { System.out.print("main"); } public void inner() { class TestInner { void print(){ System.out.print("sub"); } } TestInner inner =new TestInner(); inner.print(); print(); } } Out put : submain Question : the method print() in class Test is final and is accessible to local class , but still local class is a able to define print() method again how? If we declare private final

问题 I have a function that I'd like to call when a button is pressed, but unlike anything I've done to date, I'd like to be able to reach it from any of several ViewControllers. I don't want to have to duplicate the same chunk of code in each ViewController. I've tried defining the function I want to call outside of the ViewController class, but I can't figure out what I need to set the target to be in order to reach it. Typically self is used because the function is defined within the class, but

问题 Let's say I have a struct type Rectangle struct { length, width int } and I want to add a method to it: func (r Rectangle) Area() int { return r.length * r.width } Why must I give it a variable name here r ? 回答1: Because there is no implicit identifier denoting the actual receiver value (like this in Java), and if you want to refer to the fields or methods of the receiver value ( Rectangle value), you need an identifier that you can use. Note that the spec does not require you to name the

问题 I am writing in c++ for the Nintendo DS (With 4MB of RAM). I have a button class that stores data like the x,y location and length. Which of the following would take less memory? . Method 1 , class variables length, x, y, and halfPoint Button::Button(int setX, int setY, int setLength) { x = setX; y = setY; length = setLength; halfPoint = length/2; } //access variable with buttonName.halfPoint Method 2 , class variables length, x and y Button::Button(int setX, int setY, int length) { x = setX;

问题 This question already has answers here : Invoke direct methods or methods with arguments / variables / parameters in EL (2 answers) Closed last year . How do I call method with variable parameters in JSF? I tried something like this: <h:commandButton value="Send" action="#{myBean.checkPIN(someOtherBean.PIN)}" /> However, this doesn't work. 回答1: If you are using EL 2.2+, it's possible. If you are using older version ot EL, you can use do the following: <h:commandButton value="Send" action="#

问题 class TextToNumbers(): def __init__(self, number): self.text = str(number) self.chunks = parse_text_to_chunks(self.text) def parse_text_to_chunks(text_to_parse): #stuff This is an example of a class I'm building. I want it to define some variables with class methods on initialization. (at least I think that is what I want) I think if I talk about my end goal it is that I have a set of complex information that needs to be available about a class directly at initialization. How do I call a

问题 I noticed that if I have two methods with the same name, the first one accepts SomeObject and the second one accepts an object extending SomeObject when I call the method with SomeOtherObject , it automatically uses the one that only accepts SomeObject . If I cast SomeOtherObject to SomeObject , the method that accepts SomeObject is used, even if the object is an instanceof SomeOtherObject . This means the method is selected when compiling. Why? 回答1: That's how method overload resolution in

问题 i created a method in a new library this is my code namespace ClassLibrary1 { public class Class1 { public static bool ISprime(int prime) { if (prime < 2) return false; else if (prime == 2) return true; else { for (int i = 2; i < prime; i++) { if (prime % i == 0) return false; else return true; } } } } } how can i call that method in my console " program.cs " i got an error that said " Error 2 'ClassLibrary1.Class1.ISprime(int)': not all code paths return a value" what does that mean ? sorry