方法详解

方法是类或对象的行为特征的抽象，方法是类或对象最重要的组成部分。方法在逻辑上要么属于类，要么属于对象。如果是static方法，则该方法属于类；否则属于类的实例。

需要注意的是：同一个类的一个方法调用另外一个方法时，如果被调用方法是普通方法，则默认使用this作为调用者；如果被调用方法是静态方法，则默认使用类作为调用者。也就是说，所有方法都必须使用“对象.方法”或者“类.方法”的形式调用，而同一个类内的方法之间的调用，可以用this，也可以省略this不写，是隐式的。一个类之内的方法调用，可以调用static方法，也可以调用private方法

为了能够更好的理解static方法，类内方法的调用，static方法内调用非静态方法的结果，写了一个小程序，仅供参考

import java.util.*;public class Student{private String name;private String gender;private String phone;private String address;private String email;private int age=0;public void setter()//接收用户输入{Scanner scan = new Scanner(System.in);System.out.println("please enter name:");this.name = scan.nextLine();System.out.println("please enter gender:");this.gender = scan.nextLine();System.out.println("please enter phone:");this.phone = scan.nextLine();System.out.println("please enter address:");this.address  = scan.nextLine();System.out.println("please enter mail:");this.email = scan.nextLine();System.out.println("please enter age:");this.age = scan.nextInt();getter();//调用private方法，在同一个类内调用其他方法可以不用this前缀，但是实际上是有this的kaka();//调用static方法//search();}public void setter(String name,String gender,String phone,String address,String email,int age){this.name=name;this.gender=gender;this.phone=phone;this.address=address;this.email=email;this.age=age;System.out.println("setter running...");}private void getter()//输出方法{System.out.println("getter running...");System.out.println("your information is:");System.out.println("name\tgender\tage\tphone\t\taddress\t\t\tmail");System.out.println(name+"\t"+gender+"\t"+age+"\t"+phone+"\t"+address+"\t\t"+email);}public void search()//查找方法，功能暂时未实现{System.out.println("please enter name,email or address for looking somebody:");Scanner scan = new Scanner(System.in);String info=scan.nextLine();if(this.name==info){System.out.println("name\tgender\tage\tphone\t\taddress\t\t\tmail");System.out.println(this.name+"\t"+this.gender+"\t"+this.age+"\t"+this.phone+"\t"+this.address+"\t\t"+this.email);}else if(this.email==info){System.out.println("name\tgender\tage\tphone\t\taddress\t\t\tmail");System.out.println(name+"\t"+gender+"\t"+age+"\t"+phone+"\t"+address+"\t\t"+email);}else if(this.address==info){System.out.println("name\tgender\tage\tphone\t\taddress\t\t\tmail");System.out.println(name+"\t"+gender+"\t"+age+"\t"+phone+"\t"+address+"\t\t"+email);}else{System.out.println("can't found!");}}public void eat(){System.out.println("eat way running...");}public void drink(){System.out.println("drink way running...");}public void play(){System.out.println("play way running...");}public void sleepy(){System.out.println("sleepy way running...");}public Student fuck(){//类类型的方法需返回thisage++;return this;//必须要有返回语句}public static void kaka(){System.out.println("this is the static way!");}public static void main(String[] args){Student s1=new Student();Student[] a=new Student[100];a[0]=s1;a[0].setter();//a[0].getter();//a[0].search();//getter();//此语句无法编译，因为main方法是静态的static，而getter是非静态的//静态方法不能直接访问非静态方法，只能通过对象来调用s1.fuck();s1.fuck();s1.fuck();System.out.println("s1的age成员变量是:"+s1.age);}}

运行结果：

please enter name:
xx
please enter gender:
male
please enter phone:
12345678
please enter address:
china_beijing
please enter mail:
[e-mail]
please enter age:
26
getter running...
your information is:
name    gender  age     phone           address                 mail
xx      male    26      12345678        china_beijing           [e-mail]
this is the static way!
s1的age成员变量是:29

PS：没有考虑时间空间复杂度，仅仅是演示而已啦！