求不同图形的周长
实训目的:利用接口来实现多态。
实训要求:设计一个图形的接口,接口含求周长的抽象方法,通过定义不同图形如圆、矩形、三角形、梯形等类来实现接口中方法。通过接口类对象引用子类对象来求不同图形的周长。
代码:
interface perimeter {
public void zhouchang();
}//这里定义一个接口,接口里面放一个方法
class circle implements perimeter{
double a;
public circle (double a)
{
this.a=a;
}
public void zhouchang(){
System.out.println("这里输圆形的周长"+ (2*3.14*a));
}
}//然后定义新的类,这个类继承接口类,可以对接口类的方法进行初始化
class rectangle implements perimeter{
double a,b;
public rectangle (double a,double b){
this.a=a;
this.b=b;
}
public void zhouchang()
{
System.out.println("这里输出矩形的周长:"+((a+b)*2));
}
}
class triangle implements perimeter{
double a,b,c;
public triangle (double a,double b,double c){
this.a=a;
this.b=b;
this.c=c;
}
public void zhouchang()//chu_yu_xuan
{
System.out.println("这里输出三角形的周长"+(a+b+c));
}
}
class tixing implements perimeter{
double a,b,c,d;
public tixing (double a,double b,double c,double d){
this.a=a;
this.b=b;
this.c=c;
this.d=d;
}
public void zhouchang()
{
System.out.println("这里输出梯形的周长"+(a+b+c+d));
}
}
public class zhouchang{
public static void main (String args[]){
circle yuan = new circle(2);
rectangle juxing = new rectangle(3,4);
triangle sanjiao = new triangle(1,2,3);
tixing ti = new tixing(1,2,3,4);
yuan.zhouchang();
juxing.zhouchang();
sanjiao.zhouchang();
ti.zhouchang();
}
}