Java中方法调用详解-优快云博客

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this
				age++;
				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:
12345678@gmai.com
please enter age:
26
getter running...
your information is:
name gender age phone address mail
xx male 26 12345678 china_beijing 12345678@gmai.com
this is the static way!
s1的age成员变量是:29