20200726 千锤百炼软工人第二十一天

今天学了JAVA的克隆部分

克隆分为浅克隆和深克隆

个人理解浅克隆就是只克隆此对象的那些不是引用的属性和方法

而那些被引用的属性和方法

会让克隆产生的那个对象也引用那些属性和方法

着部分两者是共同引用的

而不是另外开辟的一部分内存来存储的信息

而深克隆就是另外开辟一部分内存来存储那些被引用的属性和方法

其次写了一个小小的继承的程序

是一个点类和圆类的程序

在此放上代码和截图

点类

package a20200725;

public class point {
private double x;
private double y;
point(double x,double y){
  this.x=x;
  this.y=y;
  System.out.print("Point Constructor run ");
}
point(){
  this.x=0;
  this.y=0;
  System.out.print("Point Constructor run ");
}
point(point p){
  this.x=p.x;
  this.y=p.y;
  System.out.print("Point CopyConstructor run ");
}
public void finalize() {
  System.out.print("Point Destructor run ");
}
public void setX(double x) {
  this.x=x;
}
public void setY(double y) {
  this.y=y;
}
public double getX() {
  return this.x;
}
public double getY() {
  return this.y;
}
public void show() {
  System.out.print("("+this.x+","+this.y+") ");
}
public double area() {
  return 0;
}
}

圆类

package a20200725;

public class Circle extends point {
private static double PI=3.14159;
private double radius;
Circle(double x,double y,double r){
  this.setX(x);
  this.setY(y);
  this.radius=r;
  System.out.print("Circle Constructor run ");
}
Circle(Circle c){
  this.setX(c.getX());
  this.setY(c.getY());
  this.radius=c.radius;
  System.out.print("Circle CopyConstructor run ");
}
Circle(){
  this.setX(0);
  this.setY(0);
  this.radius=0;
  System.out.print("Circle Constructor run ");
}
public void finalize() {
  System.out.print("Circle Destructor run ");
}
public void setRadius(double r) {
  this.radius=r;
}
public double getRadius() {
  return this.radius;
}
public double circumference() {
  return this.radius*2*PI;
}
public double area() {
  return this.radius*this.radius*PI;
}
public void show() {
  System.out.print("("+this.getX()+","+this.getY()+"),Radius="+this.radius+" ");
}
}

主函数

package a20200725;
import java.util.Scanner;
public class main {
public static void main(String[] arg) {
  double r;
  Scanner R = new Scanner(System.in);
  r = R.nextDouble();
  Circle c1 = new Circle(1,2,4);
  Circle c2 = new Circle();
  Circle c3 = new Circle(c1);
  c1.show();
  System.out.print(" Area="+c1.area()+" Circumference="+c1.circumference()+" ");
  c2.show();
  System.out.print(" Area="+c2.area()+" Circumference="+c2.circumference()+" ");
  c3.setRadius(r);
  c3.show();
  System.out.print(" Area="+c3.area()+" Circumference="+c3.circumference()+" ");
  c1=null;
  c2=null;
  c3=null;
  R=null;
  System.gc();
}
}

截图

20200726 千锤百炼软工人第二十一天

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