react class constructor

C ++ Primer: // Constref. cpp: defines console applicationsProgram.// # Include "stdafx. H" Class constref{Public:Constref (int ii ); Int I;Const int ci;Int Ri;}; Constref: constref (int ii){I = II;Ci = II;Ri = I;} // Constref: constref (int ii): I (ii), CI (I), RI (ii ){} Int _ tmain (INT argc, _ tchar * argv []){Constref B (5 ); Printf ("% d, % d, % d", B. I, B. CI, B. RI );Return 0;} In this case, there is an error in writing.

Class (1)-constructor, constructor The most basic function of the constructor is to assign an initial value to all fields and attributes of a new instance of the type. Therefore, according to its function, it does not need (or make no sense) the return value. The function name must be the same as the

As a question: New A subclass that has no constructor method invokes the parameterless constructor method of the parent class. Like the following two classes: public class Fatherclass { private int age; Public fatherclass (int age) { super (); SYSTEM.OUT.PRINTLN ("Initialization value" + age); } Public Fat

Subclasses can explicitly invoke the constructor of the parent class through the Super keyword. When the parent class does not provide a parameterless constructor, the constructor of the parent class must be explicitly called in t

Why can't constructors be virtual functions and basic class destructor?I. Why cannot constructors be virtual functions?1. From the perspective of storage space, virtual functions correspond to a pointer to the vtable virtual function table. We all know that this pointer to vtable is actually stored in the object's memory space. The problem arises. If the constructor is virtual, it needs to be called through

Each class has only one destructor, but multiple Constructors (including one default constructor, one copy constructor, and other common constructor) multiple assignment functions (including one copy assignment function, and others are normal assignment functions ). Generally, for any

information:function Actor (scene, X, y) {this.scene = Scene;this.x = X;this.y = Y;scene.register (this);}in the same way, Actor type of prototype The public method is defined on the object:Actor.prototype.moveTo = function (x, y) {this.x = X;this.y = Y;this.scene.draw ();}; Actor.prototype.exit = function () {this.scene.unregister (this); This.scene.draw ();}; Actor.prototype.draw = function () {var image = This.scene.images[this.type];this.scene.context.drawimage (image, This.x, this.y);}; Ac