inheritance

问题 I am Learning Java, while trying to understand inheritance. I couldn't figure out why the overridden method at the subclass walk() executed but not the other xyz() method. class Person{ public void walk() { System.out.println("walking like a person "); } } public class Soldier extends Person{ @override public void walk() { System.out.println("marching like a soldier "); } public void xyz() { System.out.println("xyzng like a pro"); } public static void main(String[] args) { Person sp = new

问题 I have the following classes: public interface IService { void ApplyChanges<T>(T parameters) where T : ParamBase; } public class ServiceBase : IService { public virtual void ApplyChanges<T>(T parameters) where T : ParamBase { } } public abstract class Service : ServiceBase { public override void ApplyChanges<T>(T parameters) where T : ParamBase { Console.WriteLine(parameters.Param2); //Apply changes logic here... } } public abstract class ParamBase { public string Param1 { get; set; } }

问题 I have two classes that are supposed to implement the same test cases for two independent libraries (let's call them LibA and LibB ). So far I define the test methods to be implemented in an abstract base class which ensures that both test classes implement all desired tests: from abc import ABC, abstractmethod class MyTests(ABC): @abstractmethod def test_foo(self): pass class TestsA(MyTests): def test_foo(self): pass class TestsB(MyTests): def test_foo(self): pass This works as expected, but

问题 I have been asking questions about creating a sorting method to sort a linked list of contact names read in from a text file and have advanced from my previous question:(What is a better method to sort strings alphabetically in a linked list that is reading in lines from a text file?), but am now running into two errors after creating a separate class called AlphaSorter.java with the method compareTo() which is intended to override my sort() method in my Linked List program/class called

问题 I am very confused with the inheritance right now. I planned to simply override the initial value of a variable. In the following code i just inherit the base class and try to get it's name, which is saved as a string withing the class. I expected that the derived class can override this value, however it does not do it. My expected out put was Derived Derived However i get Base Base What is the correct way to implement the following? #include <iostream> #include <string> struct Base {

问题 I am very confused with the inheritance right now. I planned to simply override the initial value of a variable. In the following code i just inherit the base class and try to get it's name, which is saved as a string withing the class. I expected that the derived class can override this value, however it does not do it. My expected out put was Derived Derived However i get Base Base What is the correct way to implement the following? #include <iostream> #include <string> struct Base {

问题 I am reviewing some code where the developer has some classes ClassA and ClassB. They both inherit from ParentClass so both must implement a number of abstract methods (e.g. return5Values(2) ) In ClassA the values are all double the previous value: [2,4,8,16,32] In ClassB the values are all +1 the previous value [2,3,4,5,6] There are also other constraints such as raising an error if the parameter is negative etc. Other tests like getting the 3rd value only, also exist etc. (Obviously these

问题 I am reviewing some code where the developer has some classes ClassA and ClassB. They both inherit from ParentClass so both must implement a number of abstract methods (e.g. return5Values(2) ) In ClassA the values are all double the previous value: [2,4,8,16,32] In ClassB the values are all +1 the previous value [2,3,4,5,6] There are also other constraints such as raising an error if the parameter is negative etc. Other tests like getting the 3rd value only, also exist etc. (Obviously these

问题 This code compiles and runs fine: #include <iostream> class Base { public: Base(int value) : clean_(true) { value_ = new int; *value_ = value; } ~Base() { if(clean_) delete value_; } Base(Base&& other) noexcept : value_{std::move(other.value_)}, clean_(true) { other.clean_=false; } Base& operator=(Base&& other) noexcept { value_ = std::move(other.value_); other.clean_=false; clean_=true; } void print() { std::cout << value_ << " : " << *value_ << std::endl; } int* value_; bool clean_; };

问题 I have my Scala classes structured as below: trait ActualClass extends ParentClass { override def method1(inputStr:String):String = { "actual "+ inputStr } def execute():String = { this.method1("test") } } trait WithClass extends ParentClass { override def method1(inputStr:String):String = { "with "+ inputStr } } class ParentClass { def method1(inputStr:String):String = { "parent "+ inputStr } } object TestClass extends App{ val actualClass = new ActualClass with WithClass { } println