<java-Object Oriented (iii) >

01. Single Case Mode:

 PackageDanli;/*** Samsung NOTE7: * Phone Model: Note7 *@authorWeguikin * * Lazy Type: * Features: Space saving * * A hungry Man: * Features: The first moment to create the object, waiting to be used*/ Public classNote7 {StaticNote7 Note;//Create a space in memory to store variable note for the custom data type of the note//non-parametric construction     PublicNote7 () {}//Create a method     Public StaticNote7 St () {if(Note = =NULL) {Note=NewNote7 (); //Note7 = new Note7 ();        }        returnNote; }}/*** A hungry man type: *@authorWeguikin **/    classNote2 {//write a class        StaticNote2 Note2 =NewNote2 ();//static loads when the class is loaded                 Public StaticNote2 GetNote2 () {returnNote2; }    }

 PackageDanli;/*** Note7: * Note This phone can only create one *@authorWeguikin **/ Public classNote7test { Public Static voidMain (string[] arge) {//Gets the method object name of the method. Method NameNote7 note1 =Note7.st (); Note7 Note2=Note7.st (); Note7 Note3=Note7.st (); Note7 note4=Note7.st ();        System.out.println (note1);        System.out.println (NOTE2);        System.out.println (Note3);                        System.out.println (NOTE4); System.out.println ("========= delimiter =================="); Note2 St=Note2.getnote2 (); Note2 NT=Note2.getnote2 (); Note2 So=Note2.getnote2 (); Note2 FE=Note2.getnote2 ();        System.out.println (ST);        SYSTEM.OUT.PRINTLN (NT);        System.out.println (SO);    SYSTEM.OUT.PRINTLN (FE); }}

02. Inheritance:

 package   extend;  /**   * Grandpa's class *   @author   Weguikin *  */ public  class   grandfather { int  money = 1200;}  

 package   extend;  /**   * Parent class: *   @author   Weguikin *  */ public  class  father extends   grandfather{ int      age;         char   gender;      // static String name = "against";  public  void       eat () {System.out.println ( I love to eat celery ... 

 package   extend;  /**   subclass *   @author   Weguikin *  */ public  class         Son extends   father {String name;  /*  public Son (int age,char gender,string Name) {//constructor}  */  @Override public  void   eat () { super      . Eat (); }}

 Packageextend;/*** Inheritance: * When we want a template, implement a variety of objects, take the code out and put it in a separate class--the stored class is called the parent class * Parent class (superclass, base class): The inherited person *             Subclass (derived Class): inheritors * Syntax: * Public class subclass name extends parent class Name {* *  * Note: * 1. One can inherit only one class directly, but other classes may be indirectly inherited * 2. If a class does not explicitly extends another class, it inherits the object class by default: A class that is a superclass of all classes * * Scope: * Subclasses can inherit all data from the parent class, including private data, but to be accessed indirectly, the constructor cannot inherit * * Benefits: * Save Code * * Method Overrides: * If the subclass and the parent class method name are identical, this method of the subclass             Called a method of rewriting * * Rewrite the place to note: * 1. The condition that constitutes the override: The return value of the method, the method name, the parameter list to be exactly the same, the range of modifiers cannot be less than the parent class * 2. Private methods and constructors cannot be overridden * 3. Static methods do not have the concept of rewriting, but can * *@authorWeguikin **/ Public classExtendtest { Public Static voidMain (string[] args) {//Creating ObjectsSon son =NewSon ();                Son.eat ();        System.out.println (Son.money);    System.out.println (Son.name); }}

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