Object-oriented Java learning four

1. What is the format of the construction method? What are the precautions?
Permission modifier class name (argument list) {method body}
Precautions:
? The construction method does not return a value type. You do not need to write a return value. Because it is for building objects, the object is created, and the method executes the end.
? The construction method name must be consistent with the type.
The constructor method does not have a specific return value.

2. Can the construction method be overloaded? Can I have a return statement inside?
Can be overloaded can have return, but cannot have returns.

3, there are several ways to assign a member variable? What's the difference?
Get/set
Direct Assignment
Assigning values with a parameter constructor
Initialization
Static code block Assignment value
Default constructor Assignment

4. Write a complete person class, using the This keyword to assign values to member variables.
Testing in a test class

 Public classPerson {PrivateString name; Private intAge ;  PublicPerson (String name,intAge ) {         This. Name =name;  This. Age =Age ; }         PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     Public intGetage () {returnAge ; }     Public voidSetage (intAge ) {         This. Age =Age ; }        }

 /     * *   * Write a complete person class and use the This keyword to assign values to member variables. Test in Test class *   @author   Vanguard *  */ public  class   Test01 { public  static  void   main (string[] args) {                Person P  = new  person ("Zhang San", 30 + "---" +p.getage ()); }}

5, as required, complete the following code (written in standard format) and test in the test class.
Standard format includes: Private property no parameter constructor with parametric constructor And getter Requirements method
demand one:
employee class employee

behavior: Show all member Information Method show ()

Requirement Two:
Animal class Animal
Attribute: Name Name, age
Behavior: Eating eat, sleeping sleep

Three requirements:
Human person
Properties: Name, age, gender gender
Behavior: Learning study, sleeping sleep

/**Employee Class Employee Attribute: Name name, work ID, wage salary behavior: Show all member Information Method show () *@authorVanguard **/ Public classEmployee {PrivateString name; PrivateString Id; Private intsalary;  PublicEmployee () {} PublicEmployee (string name, String Id,intsalary) {         This. Name =name;  This. Id =Id;  This. Salary =salary; }         PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     PublicString getId () {returnId; }     Public voidsetId (String ID) {ID=ID; }     Public intgetsalary () {returnsalary; }     Public voidSetsalary (intsalary) {         This. Salary =salary; }         Public voidShow () {SYSTEM.OUT.PRINTLN (name+ "---" + Id + "---" +salary); }}

/*** Animal Class Animal attribute: name Name, age behavior: Eat eat, sleep sleeping *@authorVanguard **/ Public classAnimal {PrivateString name; Private intAge ;  PublicAnimal () {} PublicAnimal (String name,intAge ) {         This. Name =name;  This. Age =Age ; }         PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     Public intGetage () {returnAge ; }     Public voidSetage (intAge ) {         This. Age =Age ; }         Public voideat () {System.out.println ("Food for the Animals"); }         Public voidsleep () {System.out.println ("Sleeping Animals"); }    }

/*** Animal Class Animal attribute: name Name, age behavior: Eat eat, sleep sleeping *@authorVanguard **/ Public classAnimal {PrivateString name; Private intAge ;  PublicAnimal () {} PublicAnimal (String name,intAge ) {         This. Name =name;  This. Age =Age ; }         PublicString GetName () {returnname; }     Public voidsetName (String name) { This. Name =name; }     Public intGetage () {returnAge ; }     Public voidSetage (intAge ) {         This. Age =Age ; }         Public voideat () {System.out.println ("Food for the Animals"); }         Public voidsleep () {System.out.println ("Sleeping Animals"); }    }

/*** Test class *@authorVanguard **/ Public classTest { Public Static voidMain (string[] args) {Employee em=NewEmployee ("Zhang San", "001", 5000);                Em.show (); Animal a=NewAnimal ("Little White", 2);        A.eat ();                A.sleep (); Person P=NewPerson ("John Doe", 20, "male");        P.study ();            P.sleep (); }}

Object-oriented Java learning four