一起学Java（三十五）----- 引用传递（类关联、自身关联）

不积跬步，无以至千里；不积小流，无以成江海。

 

Java语言基础

 

Java的引用传递（类关联、自身关联）

类关联实例：

有的人有汽车，有的人没有；

class Person {
	private String name;
	private int age;
	private Car car; //一个人有一辆车
	
	public Person(String name, int age) {
		this.name = name;
		this.age = age;
	}
	public String getInfo() {
		return "姓名:" + this.name + "、年龄:" + this.age;		
	}	
	public void setCar(Car car) {
		this.car = car;
	}
	public Car getCar() {
		return this.car;
	}
}

class Car {
	private String name;
	private double price;
	private Person person; //一辆车属于一个人
	public Car(String name, double price) {
		this.name = name;
		this.price = price;
	}
	public String getInfo() {
		return "汽车名字:" + this.name + "、汽车价格:" + this.price;
	}
	public void setPerson(Person person) {
		this.person = person;
	}
	public Person getPerson() {
		return this.person;
	}
}

public class Test {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Person per1 = new Person("Jiang", 24);
		Car car1 = new Car("wow", 520.0);
		per1.setCar(car1); // 一个人有一辆车
		car1.setPerson(per1); // 一辆车属于一个人
		System.out.println(per1.getCar().getInfo()); // 从人找车
		System.out.println(car1.getPerson().getInfo()); // 从车找人
	}
}

 程序输出：

汽车名字:wow、汽车价格:520.0
姓名:Jiang、年龄:24

 

 

自身关联实例：

一个人会有孩子，孩子也有车。

class Person {
	private String name;
	private int age;
	private Car car; //一个人有一辆车
	private Person children[];
	
	public Person(String name, int age) {
		this.name = name;
		this.age = age;
	}
	public String getInfo() {
		return "姓名:" + this.name + "、年龄:" + this.age;		
	}	
	public void setCar(Car car) {
		this.car = car;
	}
	public Car getCar() {
		return this.car;
	}
	public void setChildren(Person children[]) {
		this.children = children;
	}
	public Person[] getChildren() {
		return this.children;
	}
}

class Car {
	private String name;
	private double price;
	private Person person; //一辆车属于一个人
	
	public Car(String name, double price) {
		this.name = name;
		this.price = price;
	}
	public String getInfo() {
		return "汽车名字:" + this.name + "、汽车价格:" + this.price;
	}
	public void setPerson(Person person) {
		this.person = person;
	}
	public Person getPerson() {
		return this.person;
	}
}

public class Test {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Person per1 = new Person("Jiang", 24);
		
		Person child1 = new Person("wen", 1);
		child1.setCar(new Car("mom", 1314));
		
		per1.setChildren(new Person[] {child1});
		
		Car car1 = new Car("wow", 520.0);
		per1.setCar(car1); // 一个人有一辆车
		car1.setPerson(per1); // 一辆车属于一个人
		System.out.println(per1.getCar().getInfo()); // 从人找车
		System.out.println(car1.getPerson().getInfo()); // 从车找人
		// 根据人找到所有的孩子以及汽车
		for(int i = 0; i < per1.getChildren().length; i++) {
			System.out.println(per1.getChildren()[i].getInfo());
			System.out.println(per1.getChildren()[i].getCar().getInfo());
		}
	}
}

 程序输出：

汽车名字:wow、汽车价格:520.0
姓名:Jiang、年龄:24
姓名:wen、年龄:1
汽车名字:mom、汽车价格:1314.0