技術標籤：java

理解類的繼承性

1.學生資訊

class Student {
	String Name;
	int Age;
	String Degree;
	Student(String n,int a,String d) {
		Name=n;
		Age=a;
		Degree=d;
	}
}
class Undergraduate extends Student {
	String Professional;
	Undergraduate(String n,int a,String d,String p) {
		super(n,a,d);
		Professional=p;
 

	}
	void show() {
		System.out.println("本科生:\t姓名:"+Name+"\t年齡:"+Age+"\t學位:"+Degree+"\t專業:"+Professional);
	}
}
class Master extends Student {
	String Direction;
	Master(String n,int a,String d,String dir) {
		super(n,a,d);
		Direction=dir;
	}
	void show() {
		System.
 
out.println("研究生:\t姓名:"+Name+"\t年齡:"+Age+"\t學位:"+Degree+"\t研究方向:"+Direction);
	}
}
public class MyStudent {
	public static void main(String args[]) {
		Undergraduate undergraduate=new Undergraduate("張三",20,"學士","軟體工程");
		Master master=
 
new Master("李四",25,"碩士","網路工程");
		undergraduate.show();
		master.show();
	}
}

2.車輪數量

class Car {
	int Number;
	int Weight;
	Car(int n,int w){
		Number=n;
		Weight=w;
	}
}
class Truck extends Car {
	int Load;
	Truck(int n, int w,int l) {
		super(n, w);
		Load=l;
	}
	void show() {
		System.out.println("卡車:\t車輪個數:"+Number+"\t車重:"+Weight+"\t載重量:"+Load);
	}
}
class Van extends Car{
	int Busload;
	Van(int n, int w,int b) {
		super(n, w);
		Busload=b;
	}
	void show() {
		System.out.println("麵包車:\t車輪個數:"+Number+"\t車重:"+Weight+"\t載客量:"+Busload);
	}
}
public class MyCar {
	public static void main(String args[]) {
		Truck truck=new Truck(16,2000,5000);
		Van van=new Van(8,1000,12);
		truck.show();
		van.show();
	}
}

3.圓柱體

class Circle {
	public static final double PI=3.14;
	int X;
	int Y;
	double R;
	Circle(int x,int y,double r) {
		X=x;
		Y=y;
		R=r;
	}
	int getX() {
		return X;
	}
	int getY() {
		return Y;
	}
	double getR() {
		return R;
	}
	void perimeter() {
		double l;
		l=2*PI*R;
		System.out.println("周長:"+l);
	}
	void area() {
		double a;
		a=PI*R*R;
		System.out.println("面積:"+a);
	}
}
class Cylinder extends Circle {
	Cylinder(int x, int y, double r) {
		super(x, y, r);
	}
	double High;
	void sethigh(double h) {
		High=h;
	}
	double getHigh() {
		return High;
	}
	void area(){
		double a;
		a=2*PI*R*R+2*PI*R*High;
		System.out.println("表面積:"+a);
	}
	void volume(){
		double v;
		v=PI*R*R*High;
		System.out.print("體積:"+v);
	}
}
public class MyCircle {
	public static void main(String args[]) {
		Cylinder cylinder=new Cylinder(0,0,2);
		cylinder.sethigh(2);
		System.out.println("圓柱體資訊:\n座標:("+cylinder.X+","+cylinder.Y+")\t底面半徑:"+cylinder.R+"\t高度:"+cylinder.High);
		cylinder.area();
		cylinder.volume();
	}
}