Behavior of the object

The behavior of the object:

1, master the Declaration and invocation of the class method;

2, understand the method call stack;

1), the invocation of the method;

2), select the statement;

3), cyclic statements;

3, understand the method of overloading;

4, the understanding of the construction device;

☆ Object-oriented First principle: Single duty (one way to do a thing)

Code Analysis:

(a):

public class date{

Public Int. Day, month, Ysar;

public int GetDay () {

Systen.out.println ("Within the Getday method");

Return day;

}

Publiv void PrintDate () {

System.out.println ("Within the PrintDate method");

SYSTEM.OUT.PRINTLN (month + "/" + Day + "/" + year);

}

}

Two

public class dateprogram{

public static void Main (String [] args) {//1, enter main run

System.out.printlin ("Inside the Main method ..."); 2. Print in console: Inside the Main method ...

Date today = new Date;

Today.day = 2; Set Month: 2

Today.month = 14; Set Date: 14

Today.year = 2009; Set Year: 2009

System.out.println ("Days are:" + today.getday ()); 3, 1): Call "Today.getday" into (a):p ublic int GetDay () {

Printing in console: Inside the Getday method

2): Print in console: Number of days: 2

System.out.println ("Print date ..."); 4. Print in console: print date ....

Today.printdate (); 5, 1): Call "Today.printdate" into (a): Publiv void PrintDate () {

Printing in console: Inside the PrintDate method

Print in console: 14/2/2009 (based on print arrangement: Month + "/" + Day + "/" + year)

System.out.println ("What is the next display?")　　　　　　　　 "); 6, in the console printing: What is the next display content?

Today.getday (); 7. Call "Today.getday" to enter (a):p ublic int GetDay () {

Printing in console: Inside the Getday method

}

}

Method Signature:

The signature of a method includes information such as the method name, the parameter list, the data type of the return value, and so on.

Method overloads:

A class has two different methods to multiple names but different parameter lists.

Type, number

First, there are no arguments:

"Non-parametric construction"

Public Preson () {

　　　　

}

"With a reference to the structure"

Public person (String [] args) {

Example this.name= name;

Example this.age = 18;

Example This.gender =true;

}

☆ Boolean : Boolean in Get/set method　 ;

The automatically generated get method generates data as:"is." Gender " not applicable with existing methods need to be changed manually

Manual change: Change data to: "Get." Gender "

Constructor:

Role: Generating objects

Memory Area Division: 4 Zones

Heap area: New data: Basic data

Stack area: Local variables

Data segments: reference types, String constants

Code snippet:

This

This:1): Property, 2) method This refers to the current object.

This (): a constructor method calls the other construction method of this class, so as to achieve the construction method code reuse;

Can only be written in the first sentence of the construction method

Behavior of the object