Anonymous classes and wrappers for Java classes

/* Anonymous object: No reference type variable points to an object called an anonymous object. Requirements:  Use the  java class to describe a student class. Things to note for anonymous objects:1.  we generally do not assign property values to anonymous objects because they are never available. 2.  two anonymous objects can never be the same object. Anonymous object benefits: Simplify writing. The object's heap memory space can be freed as soon as possible application scenarios for anonymous objects:1.  if an object needs to call a method one time, and after the method is called, the object is no longer used, and an anonymous object can be used. 2.  can call a function as an argument. *///Student Class class student{    int num; //No.     String  name; //name     public void study () {         SYSTEM.OUT.PRINTLN ("Study hard, prepare for what will be called Gao!");     }}class demo4{    public static void main ( String[] args)      {        //Create a Student object         //student s = new student ();         //new student () .name =  "Dog Doll";  //Anonymous Object           //system.out.println (Student (). name);  //null        system.out.println (new  Student ()  == new student ())  ;  //  "= ="   When used to reference a type variable, the memory address is compared. Determines whether two objects are the same object         //demand:  calls student study method.         student s = new student ();         s.study ();         new student (). Study ();     }}

package com.fish.object;/* three characteristics of object-oriented:1.  encapsulation 2.  inheritance 3.  polymorphism. Requirements:   use Java class to describe the members of Lily Net. Question:  sex have problem?? Root cause:  Because other people can manipulate the sex attribute directly. You can assign a direct value to the sex attribute. Encapsulation: Permission modifier: the permission modifier is the visible range of the control variable. public :   the public.  public modified member variables or methods can be accessed directly by anyone. private :  Private,  private-modified member variables or methods can only be accessed directly in this class. The encapsulated step:1.  uses the private adornment property that needs to be encapsulated. 2.  provides a common way to set or get the private member property.   Naming specification: Set property name (); Get property name ();  doubt:  package must provide a get or set method? Not necessarily,  on demand. Don't want someone else to modify or access it does not provide a GET or set method specification  :  all member properties (member variables) of a generic entity class are encapsulated in real-world development. Entity classes: Entity classes are used to describe a class of   things called entity classes. Tool classes (tool classes for arrays arrays): The benefits of encapsulation:1.  improve the security of your data. The 2.  is simple to operate.  3.  hides the implementation. */class member{    publicstring name; //name      privatestring sex; //Sex     publicint salary; //Salary          //defines a common method for setting the Sex property     public void setsex (String  s) {        if  (S.equals ("male") | | S.equals ("female")) { //Note:  If you compare the contents of two strings, do not use = = to compare,  using the Equals method. Comparison of basic data types can be used = =, such as character type             sex = s;         }else{             //By default is male             sex =   "Male";         }    }    // Defines a common way to get the sex attribute     public string getsex () {         return sex;    }    //Chat      Public void talk () {        system.out.println (name+ "very happy chat") ;     }}class demo5{public static void main (String[] args)  {     membEr m = new member ();     m.name= "Zhao";     m.setsex ("     m.salary  = 800;    system.out.println ("Name:" +  m.name+ "  Gender:" + m.getsex () + "  Salary:" + m.salary);}

package com.fish.object;/* Requirements:  Use the Java class to describe a calculator class, the calculator has the operand 1,  operand 2 , the operator three public   properties, but also has the computational function behavior.   requires that:  not be directly assigned to the operand 1, operand 2, operator of these properties for direct  , to be encapsulated.   (+ - * /  ) provides a get or set method as required. You need to provide the Set method *///Calculator class class calculator{private int num1; //operand 1private int num2;   //operand 2 privatechar option ; //operator//provides a common method for setting property values ....public void  Initcalculator (Int n1 , int n2 , char o) {num1 = n1;num2 =  n2;if (o== ' + ' | | o== '-' | | o== ' * ' | | o== '/') {Option = o;} else{option =  ' + ';}} The computed function public void calculate () {switch (option) {case  ' + ': System.out.println ("Do the addition operation, the result is:" + (num1+ num2));break;case  '-': System.out.println ("Do subtraction, the result is:" + (NUM1-NUM2));break;case  ' * ': System.out.println ("Do the multiplication, the result is:" + (NUM1*NUM2));break;case  '/': System.out.println ("Do the division operation, the result is:" + (num1/num2)); Class demo6 {public static void main (String[] args)  {//created a Calculator object Calculator c = new calculator () ;//Set the property value C.initcalculator ("a");//Call Calculator's calculation function c.calculate ();}}

package com.fish.object;/* demand:  currently exists array: int[] arr = {0,0,12,1,0,4,6,0}  Write a function to receive the array , then clears the array of 0 and returns an array that does not exist with the 0 element. Step:1.  The length of the new array of computers.    original Array length-number of 0 */import java.util.*;class demo7{    public static  void main (String[] args) {        int[] arr =  {0,0,12,1,0,4,6,0};        arr = clearzero (arr);         system.out.println ("Elements of the array:" +arrays.tostring (arr));     }    public static  int[] clearzero (Int[] arr) {         //number of statistics 0         int count  = 0;//defines the number of a variable record 0         for (int i = 0  ; i<arr.length ; i++) {         if (arr[i]==0) {            count++;         }    }    //Create a new array     int[] newArr = new int[arr.length-count];     int index  =0 ; //the index value used by the new array     //stores the non-data in the new array.     for (int i = 0; i<arr.length ; i++) {         if (arr[i]!=0) {             newArr[index] = arr[i];             index++;        }    }     return newarr;    }}

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Anonymous classes and wrappers for Java classes