child class

  Question: for example, question. Assume that there are parent class A and Child class B. A instantiate an object a B instantiate an object B What is the address relationship between A and B in the memory. Are their first addresses the same?

1, Father.javaPackage Com.ljb.extend;public class Father {public int x = ten; public int fget () {return x;}}2, Son.javapackage com.ljb.extend;public class  son extends father { //  cannot appear with the parent class with the same name property

Class A{public:void Funca () { printf ("Funca called\n");} virtual void Funcb () { printf ("FUNCB called\n");} };class b:public a{public:void Funca () { A::funca (); printf ("Funcab called\n"); } virtual void Funcb () { printf

4 , indicating the running result of the following program. Class A {static {System.out.print ("1");}Public A () {System.out.print ("2");}}Class B extends a{static {System.out.print ("a");}Public B () {System.out.print ("B");}}public class Hello

Try to understand from the memory angle of the object.Suppose that there is now a parent class father, the variables inside it need to occupy 1 m of memory. There is a subclass of it that has a variable that takes up 0.5M of memory.Now let's look at

Class B extends A, then the type a is the parent class with static code blocks, common code blocks, static methods, static member variables, ordinary member variables, common methods.Subclasses are also like this, and then inherit the results about

For Java, a normal language, subclasses can call non-private variables in the parent class, but in some special casesThe Java language can invoke variables of subclasses through the parent classIn particular, please follow the example below!Package

Public class Animal {Public static void Main (string[] args) {Animal Animal = new Cat ();Animal.voice ();Drinkwater (animal); Call a static method, passing in a subclass object referenced by the parent class }String str;Public void Voice ()

//Inheritance of Classes#include using namespacestd;/*Parent-child relationship between inheriting classes in object-oriented 1. Subclasses have all member properties and member functions (including private member variables) of the parent Class 2.

Subclasses sometimes need to execute the parent class's constructor method Class Annimal (object): def __init__ (self): print (' bar ') self.type = ' Animal ' class Shengwu (object): def _ _init__ (self): print (' Sengwu

(I am a newbie, new C ++) In general, the base class and the derived class (that is, the parent class and subclass) both contain Constructors (called when the class is created) and destructor (called when a class is deleted ). What is the sequence

// Ex_exam.cpp: defines the entry point of the console application. // # Include "stdafx. H "# include using namespace STD; Class A {public: Virtual void Foo () {cout Foo (); pa-> PP (); If (B * pb = dynamic_cast (PA )) {cout (PA)-> functionb ();

Cashapelayer Cashapelayer is a layer subclass that is drawn by vector graphics instead of bitmap. You specify attributes such as color and line width, and cgpath to define the graphic you want to draw, and the Cashapelayer is automatically rendered.

加两个字段,一个是父ID,如果是顶层,父ID就为0,一个是是否有下级,0元1有,一个函数就可解决,在函数中间调用本函数,找出了父层,再找他是否有下级,如果有,再找父ID为本ID的栏目 '==================================================' Procedure name: Listecityclass' Function: Display system classification' Parameter: ID------the system

Look at the introduction of Datastore, and began to use the MVC way to write PHP, so want to take PHP for Redis to write a model, you can achieve some of the basic functions of datastore ... So I came across a question-.-PHP __class__ This kind of

concept of inheritance:Inheritance is special in its own--general relationship, that is, often said is-a relationship. The subclass inherits the parent class, indicating that the subclass is a special parent class and has some properties or methods

C # OO (elementary idea )., Inheritance, polymorphism, encapsulation In C #, In order to reasonably describe the laws of nature, object-oriented programming introduces the concept of inheritance, which is one of the most important concepts in object-

An overview of object-oriented thinking :Lprogrammers are transformed from performers into conductors. Lwhen the requirement is complete:?go first.Find theRequired Functionsthe object touse. ?if the object does not exist, create an object with the

For object-oriented programming languages, inheritance and polymorphism are the two most basic concepts. Hibernate's inheritance mapping can understand the inheritance relationships between persisted classes. For example: the relationship between

This blog post describes the various stages of the bytecode file loading process ... The focus needs to be on what the JVM needs to do at each stage ... Overview Global---- class files are loaded through various stages: In Java application