今天完成了一个小程序
是一个圆类
其中感受到了java程序中析构函数,构造函数等等一系列的差别
在此附上代码和运行截图
package a20200720;
public class Circle {
public static double PI=3.1415;
private double radius;
Circle(double a){
this.radius=a;
System.out.print("Constructor run");
}
Circle(){
this.radius=0;
System.out.print("Constructor run");
}
public void finalize() {
System.out.print("Destructor run");
}
Circle(Circle a){
this.radius=a.radius;
System.out.print("CopyConstructor run");
}
public void setRadius(double r) {
this.radius=r;
}
public double getRadius() {
return radius;
}
public double circumference() {
return PI*2*radius;
}
public double area() {
return PI*radius*radius;
}
double fCircle_L(Circle r) {
return PI*2*r.radius;
}
double fCircle_S(Circle r) {
return PI*r.radius*r.radius;
}
}
public static double PI=3.1415;
private double radius;
Circle(double a){
this.radius=a;
System.out.print("Constructor run");
}
Circle(){
this.radius=0;
System.out.print("Constructor run");
}
public void finalize() {
System.out.print("Destructor run");
}
Circle(Circle a){
this.radius=a.radius;
System.out.print("CopyConstructor run");
}
public void setRadius(double r) {
this.radius=r;
}
public double getRadius() {
return radius;
}
public double circumference() {
return PI*2*radius;
}
public double area() {
return PI*radius*radius;
}
double fCircle_L(Circle r) {
return PI*2*r.radius;
}
double fCircle_S(Circle r) {
return PI*r.radius*r.radius;
}
}
package a20200720;
import a20200720.Circle;
import java.util.Scanner;
public class Circlemain {
public static void main(String[] arg) {
Scanner r=new Scanner(System.in);
double a=r.nextDouble();
Circle c1=new Circle(a);
System.out.print(" ");
c1.setRadius(a);
System.out.print(c1.circumference()+" ");
System.out.print(c1.area()+" ");
Circle c2=new Circle(c1);
System.out.print(" ");
System.out.print(c2.fCircle_L(c2)+" ");
System.out.print(c2.fCircle_S(c2)+" ");
c1=c2=null;
System.gc();
}
}
import a20200720.Circle;
import java.util.Scanner;
public class Circlemain {
public static void main(String[] arg) {
Scanner r=new Scanner(System.in);
double a=r.nextDouble();
Circle c1=new Circle(a);
System.out.print(" ");
c1.setRadius(a);
System.out.print(c1.circumference()+" ");
System.out.print(c1.area()+" ");
Circle c2=new Circle(c1);
System.out.print(" ");
System.out.print(c2.fCircle_L(c2)+" ");
System.out.print(c2.fCircle_S(c2)+" ");
c1=c2=null;
System.gc();
}
}