oop

问题 I know how virtual works in the context of member functions, but I saw an article online about virtual member classes that confuses me. The example I found is this: class Machine { void run () {} virtual class Parts { }; }; // The inner class "Parts" of the class "Machine" may return the number of wheels the machine has. class Car: public Machine { void run() { cout << "The car is running." << endl; } class Parts { int get_Wheels () { cout << "A car has 4 wheels." << endl; return 4; } string

问题 This question already has an answer here : What happens in the heap when class A inherits class B in Java (1 answer) Closed 1 year ago . Consider a Superclass A and a derived class B whereas A contains a private variable x . B contains an explicit super() call as first argument inside its constructor while there might be some other variables of B like y and z . As far as I know there is no inheritance for private fields. Does that mean private fields will not get instantiated while executing:

问题 "How to iterate through CSV data from PowerShell ?" would perhaps be an alternate question title. This output is fine: PS /home/nicholas> PS /home/nicholas> $flat Date Region New_Tests Total_Tests Positivity Turn_Around ---- ------ --------- ----------- ---------- ----------- 2020-01-23 BC 2 2 0 32 2020-01-23 Fraser 0 0 0 0 2020-01-23 Interior 0 0 0 0 2020-01-23 Northern 0 0 0 0 2020-01-23 Unknown 0 0 0 0 2020-01-23 Vancouver Coastal 2 2 0 32 2020-01-23 Vancouver Island 0 0 0 0 .. but I'd be

问题 "How to iterate through CSV data from PowerShell ?" would perhaps be an alternate question title. This output is fine: PS /home/nicholas> PS /home/nicholas> $flat Date Region New_Tests Total_Tests Positivity Turn_Around ---- ------ --------- ----------- ---------- ----------- 2020-01-23 BC 2 2 0 32 2020-01-23 Fraser 0 0 0 0 2020-01-23 Interior 0 0 0 0 2020-01-23 Northern 0 0 0 0 2020-01-23 Unknown 0 0 0 0 2020-01-23 Vancouver Coastal 2 2 0 32 2020-01-23 Vancouver Island 0 0 0 0 .. but I'd be

问题 #include iostream #include cmath #include fstream #include cstdlib #include string using namespace std; class Device {//Input and store Device Description and Serial Numbers protected: string serial_number; string device_description; public: Device() { serial_number = ("6DCMQ32"); device_description = ("TheDell"); } }; class Test {//Input and store Test Description, recent day, and month; Calculate the next day protected: string Test_Description; static int recent_month, recent_day, recent

问题 I have been building a RTS to improve my Java skills. I have been reading a lot about the Law of Demeter because I want to keep my code clean but I'm still quite confused! At the moment I have some code like this in the view to show how many of a certain ship there are in a fleet on the selected planet: int numberOfFrigates = model.getSelectedPlanet().getFleet().getNumberOfFrigates(); Which from what I understand goes against the Law of Demeter. If I'm only supposed to have 'one dot' do I

问题 I'm trying to create a large object whose values are limited to only 3 types: Texture , Geometry , Script My object would look something like this: var assets: Assets = { sky: <Texture>, ground: <Texture>, city: <Geometry>, people: <Script>, cars: <Script>, sun: <Circle> // <--This should fail because it's not one of the 3 types //... } How can I declare the Assets interface so the value in each key-value pair is limited to these 3 types? I tried starting with: interface Assets{ key: Texture

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 2 years ago . Improve this question I wish to create a helper class with public static methods only. I declare a class instead of namespace, because I will befriend this class with others so that it can operate on their private members as well. Is this considered a bad OOP practice? Is there an

问题 The Python API is available to read objects from a cluster. By cloning we can say: Get a copy of an existing Kubernetes object using kubectl get Change the properties of the object Apply the new object Until recently, the option to --export api was deprecated in 1.14. How can we use the Python Kubernetes API to do the steps from 1-3 described above? There are multiple questions about how to extract the code from Python API to YAML, but it's unclear how to transform the Kubernetes API object.

问题 Given this code: trait Base { fn a(&self); fn b(&self); fn c(&self); fn d(&self); } trait Derived : Base { fn e(&self); fn f(&self); fn g(&self); } struct S; impl Derived for S { fn e(&self) {} fn f(&self) {} fn g(&self) {} } impl Base for S { fn a(&self) {} fn b(&self) {} fn c(&self) {} fn d(&self) {} } Unfortunately, I cannot cast &Derived to &Base : fn example(v: &Derived) { v as &Base; } error[E0605]: non-primitive cast: `&Derived` as `&Base` --> src/main.rs:30:5 | 30 | v as &Base; | ^^^^