shadowing

问题 This question already has answers here : Why does an overridden function in the derived class hide other overloads of the base class? (4 answers) Closed 4 years ago . Given the following... #include <iostream> using namespace std; class BaseClass { public: void Func(float f) { cout << "BaseClass:Func() called!"; } }; class SubClass : public BaseClass { }; int main() { SubClass sub; sub.Func(1.1f); return 0; } This runs pretty much as one would expect, resulting in the following output...

问题 let print_scene (y, v) = do Console.Clear() let y, v = int y, int v (* This is the code in question *) for j = 10 downto 0 do for i = 0 to 30 do if (y + 1) = j && i = 15 then Console.Write("b") elif j = 0 || i = 0 || j = 10 || i = 30 then Console.Write("*") else Console.Write(" ") Console.Write("\n") ignore(Console.ReadKey()) I don't understand what the int is doing in this code, what it is, or why it's there. 回答1: Indeed, this is parameter shadowing. let foo bar = let bar = bar * bar bar

问题 Here is the code snippet in question: package main import ( "fmt" ) var a string = "hello" func main() { b := "world" fmt.Println(a, b) a := "bye" fmt.Println(a, b) } Output: hello world bye world My question is, how do I resolve name clash between the "global" and "local" variables a ? More specifically, how do I tell Go which a to use? 回答1: I think your original example illustrates the situation well. Just like most in programming languages the scope matters. The scoping closest to the use

问题 The case of shadowing class variables is common in in Java. Eclipse will happily generate this code: public class TestClass { private int value; private String test; public TestClass(int value, String test) { super(); this.value = value; this.test = test; } public int getValue() { return value; } public void setValue(int value) { this.value = value; } public String getTest() { return test; } public void setTest(String test) { this.test = test; } } Is variable shadowing ever ok? I am

问题 The case of shadowing class variables is common in in Java. Eclipse will happily generate this code: public class TestClass { private int value; private String test; public TestClass(int value, String test) { super(); this.value = value; this.test = test; } public int getValue() { return value; } public void setValue(int value) { this.value = value; } public String getTest() { return test; } public void setTest(String test) { this.test = test; } } Is variable shadowing ever ok? I am

问题 I am struggling to understand Variables Shadowed Methods Overriden Concept of inheritance with Java. Case 1: class Car{ public int gearRatio = 8; public String accelerate() { return "Accelerate : Car"; } } class SportsCar extends Car{ public int gearRatio = 9; public String accelerate() { return "Accelerate : SportsCar"; } public static void main(String[] args){ Car c = new SportsCar(); System.out.println( c.gearRatio+" "+c.accelerate() ); } } Output: 8 Accelerate : Sportscar. Case 2: public

问题 Basically I would like to know why a static method cannot be shadowed by an instance method, (I know why, it will lead to ambiguity in certain circumstances), whereas a static variable can be shadowed by an instance variable (it applies only for subclasses). Example: public class Apartment{ static int area = 10; public static int getArea(){ return area; } } class BedroomFlat extends Apartment { int area = 10;// no problem at all public int getArea(){ // illegal line it cannot hide the super

问题 I'm trying to learn java by myself, and am looking to make a secure text editor that you have to log into to access the text. However, the action listener isn't working for any of the buttons, and i can't figure out what's wrong. Please note I've made two buttons only because the first didn't work. My code is below: public class storage extends JFrame{ private JTextField text1; public JTextArea storearea; public JButton newsave; public JButton save; public storage(UserProfile person) { /

问题 I have a data frame that looks like this: #df ID DRUG FED AUC0t Tmax Cmax 1 1 0 100 5 20 2 1 1 200 6 25 3 0 1 NA 2 30 4 0 0 150 6 65 Ans so on. I want to summarize some statistics on AUC, Tmax and Cmax by drug DRUG and FED STATUS FED . I use dplyr. For example: for the AUC: CI90lo <- function(x) quantile(x, probs=0.05, na.rm=TRUE) CI90hi <- function(x) quantile(x, probs=0.95, na.rm=TRUE) summary <- df %>% group_by(DRUG,FED) %>% summarize(mean=mean(AUC0t, na.rm=TRUE), low = CI90lo(AUC0t), high

问题 If I write the following F# code, the compiler issues an error. let a = 123 let a = 123 The error produced is: error FS0037: Duplicate definition of value 'a' If I write the same code in a function like this: let fctn = let a =123 let a =123 a it doesn't produce any error. I don't understand the difference. Can anyone please explain? Edit : first code I write in module level. 回答1: I agree this is confusing. The problem is that let behaves differently when it is used as a local variable