我正在为学校建立一个实验室,它即将完成,但有一个部分我无法开始工作。继承有效,除非我到达 Cube。由于某种原因,它不会计算面积或体积(它只是得出 0)。我认为这是我从 Square 到 Cube 的继承方式的问题。帮助会很棒!
package InheritanceTest;
import javax.swing.JOptionPane;
public class InheritanceTest {
public static void main(String[] args) {
String input = "";
Point point = new Point();
input = getinput("Set variable X");
point.setx(input);
input = getinput("Set variable Y");
point.sety(input);
System.out.println("Point, x = " + point.getx() + " y = " + point.gety());
Square square = new Square();
input = getinput("Set variable Side Length");
square.setSideLength(input);
System.out.println("Square, x = " + point.getx() + " y = " + point.gety()
+ " Area = " + square.getAreaOfSquare() + " Perimeter = "
+ square.getPerimeterOfSquare());
Cube cube = new Cube();
input = getinput("Set variable depth");
cube.setDepth(input);
System.out.println("cube, x = " + point.getx() + " y = " + point.gety()
+ " Depth = " + cube.getDepth() + " Area = " + cube.getAreaOfCube()
+ " Volume = " + cube.getVolumeOfCube());
}
private static String getinput(String string) {
String x = JOptionPane.showInputDialog(string);
return x;
}
}
package InheritanceTest;
public class Cube extends Square {
private int depth;
Cube() {
super();
depth = 0;
}
Cube(int x, int y, int sideLength, int d) {
super(x, y, sideLength);
this.depth = d;
}
public int getAreaOfCube() {
return (6 * sideLength * sideLength);
}
public int getVolumeOfCube() {
return (sideLength * sideLength * sideLength);
}
public String getDepth() {
return Integer.toString(depth);
}
public void setDepth(String i) {
depth = Integer.parseInt(i);
}
}
package InheritanceTest;
public class Point {
private int x;
private int y;
Point() {
x = 0;
y = 0;
}
Point(int x, int y) {
this.x = x;
this.y = y;
}
public String getx() {
return Integer.toString(x);
}
public String gety() {
return Integer.toString(y);
}
public void setx(String input) {
x = Integer.parseInt(input);
}
public void sety(String input) {
y = Integer.parseInt(input);
}
}
package InheritanceTest;
public class Square extends Point {
protected int sideLength;
Square() {
super();
sideLength = 0;
}
Square(int x, int y, int l) {
super(x, y);
this.sideLength = l;
}
public int getAreaOfSquare() {
return sideLength * sideLength;
}
public int getPerimeterOfSquare() {
return sideLength + sideLength;
}
public String getSideLength() {
return Integer.toString(sideLength);
}
public void setSideLength(String input) {
sideLength = Integer.parseInt(input);
}
}
最佳答案
当您创建立方体(new Cube())时,您没有为其延伸的方形对象设置边长(或 x 和 y)。
Cube(){
// This is the constructor called.
super();
depth = 0;
}
Cube(int x, int y, int sideLength, int d){
super(x, y, sideLength);
this.depth = d;
}
您可能希望将 x、y 和长度值提取到变量中并使用“new Cube(x, y, length, depth)”
类似下面的内容
String x = getinput("Set variable X");
String y = getinput("Set variable Y");
String sideLength = getinput("Set variable Side Length");
String depth getinput("Set variable depth");
Cube cube = new Cube(x, y, sideLength, depth);
关于java - 多级继承不起作用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20184976/