oop

问题 Object.Equals always return false, Why not equal? Student student = new Student(3, "Jack Poly"); Student otherStudent = (Student)student.Clone(); if (Object.Equals(student, otherStudent)) { Console.WriteLine("Equal"); } else { Console.WriteLine("Not Equal"); } Clone method like below public override StudentPrototype Clone() { return this.MemberwiseClone() as StudentPrototype; } 回答1: Look at this article MSDN If the current instance is a reference type, the Equals(Object) method tests for

问题 I'm new to OOP and I can't figure out why this isn't working. Is it not ok to instantiate a class with in a class. I've tried this with included file with in the method and it didn't make a change. include('Activate.php'); class First { function __construct() { $this->activate(); } private function activate() { $go = new Activate('Approved'); } } $run = new First(); 回答1: Are you saying that you want to access $go ? because, if that is the case, you need to change the scope of it. As you see,

问题 I'm new to OOP and I can't figure out why this isn't working. Is it not ok to instantiate a class with in a class. I've tried this with included file with in the method and it didn't make a change. include('Activate.php'); class First { function __construct() { $this->activate(); } private function activate() { $go = new Activate('Approved'); } } $run = new First(); 回答1: Are you saying that you want to access $go ? because, if that is the case, you need to change the scope of it. As you see,

问题 What is the normal practice when it comes to non-member function in C++? Do we put them in main.cpp or header file or class implementation file, or do we make a separate .cpp file for it? If the normal practice is to make a separate file, then where do we put the non-member function header(prototype)? Does it only go in main.cpp or in both of them? 回答1: I would say you should not treat non-member functions differently to classes and member functions and other symbols. You should create a

问题 When I am creating an array of Example objects, I call something like initializeArray(); I use a simple nested for loop to traverse through the array and then assign new objects with values to each index of the array using exampleArr[i][j] = new Example(false, false, false, 0); however, calling this gives me an java.lang.ArrayIndexOutofBoundsException:0 at the line above. I am assuming that I am instantiating the new object incorrectly, as this also happens in another method which is supposed

问题 When I write jQuery code, I use $(this) to change element: $('.classname').click(function(){ $(this).toggleClass('collapsed'); // .. }); Now I have are javascript class, looks like this: class CabinetFormSize { constructor() { this.cabinetBTN = $(".cabinetBTN"); this.events(); } events() { this.cabinetBTN.click(this.toggleMenu.bind(this)); } toggleMenu() { console.log($(this)); this.cabinetBTN.toggleClass('d-none'); } } If i write this in toggleMenu() I have class instance, but I need the

问题 String is a class in java. While declaring and assigning string, it is correct to say String name = "Paul" though to instantiate an object from a java class we do String name = new String(); Taking name as an object, I'm wondering why we can assign a series of characters "Paul" to the object. Under what concept does this one works and how does it? 回答1: That's because implicitly Strings - "..." are treated as objects as well. Under the cover JVM looks for similar "objects" in so called String

问题 This question already has answers here : What is abstraction? [closed] (4 answers) Closed 1 year ago . I am confused in between many definitions of abstraction. can any one tell me what is abstraction and how can we achieve it ? 回答1: Abstraction in OOP theory consists in retaining only the relevant aspects of a real world object for a specific problem . Thus we talk about abstraction of the reality . It's a reduction . For example, in the real world we have cats and dogs that are vertebrate

问题 I need a table variable in a Lua class, which is unique for each instance of the class. In the example listed below the variable self.element seems to be a static variable, that is used by all class instances. How do I have to change the testClass to get a non static self.element table variable? Example: local testClass ={dataSize=0, elementSize=0, element = {} } function testClass:new (data) local o = {} setmetatable(o, self) self.__index = self -- table to store the parts of the element

问题 Hey I'm a beginner programmer who is starting with python and am starting out by making a game in pygames. The game basically spawns in circles at random positions, and when clicked give you points. Recently i've hit a roadblock when I want to spawn in multiple instances of the same object(in this case circles) at the same time. I've tried stuff like sleep() and some other code related to counters, but it always results in the next circle spawned overriding the previous one(i.e the program