所以我的目标是让一个程序工作，有多种方法来操作矩形。所以我的大部分代码都可以工作，但是当我使用我的测试器时，我会遇到错误。任何insite都会非常感激！ 首先是我的Tester Class。
public class MyTester {
public static void main(String[] args) {
Rectangle i = new Rectangle(5,8);
Rectangle p = new Rectangle(8,5);
Rectangle o = new Rectangle(4);
Rectangle n = new Rectangle();
System.out.println("---------------------------------------------------------------"); //line seperation per testers
//this prints out the width and height to the user (2 arg construct)
System.out.println("i width: " + i.getWidth() + "\n" + "i height: " + i.getHeight());
System.out.println("---------------------------------------------------------------");
//This prints out the width and height to the user (1 arg construct)
System.out.println("o width: " + o.getWidth() + "\n" + "o height: " + o.getHeight());
System.out.println("---------------------------------------------------------------");
System.out.println("n width: " + n.getWidth() + "\n" + "n height: " + n.getHeight());
System.out.println("---------------------------------------------------------------");
System.out.println("Here is the duplicate d of rectangle duplicate: ");// rectangleDuplicate
System.out.println("Fix this sections of the tester and code!");
System.out.println("---------------------------------------------------------------");
//This prints out to the user if Rectangles are equal or not
System.out.println(i.equals(p));
System.out.println("---------------------------------------------------------------");
//This prints out to the user the new width and height after rotating
System.out.println(i.rotate());
System.out.println("---------------------------------------------------------------");
//This prints out to the user the area of the selected rectangle
System.out.println("The area of Rectangle o: " + o.getArea());
System.out.println("---------------------------------------------------------------");
//This prints out to the user the diagonal of the Rectangle selected
System.out.println("The diagonal of Rectangle p: " + p.getDiagonal());
System.out.println("---------------------------------------------------------------");
System.out.println("A copy of Rectangle i: " + i.copy());//.copy
System.out.println("Fix this sections of the tester and code!");
System.out.println("---------------------------------------------------------------");
System.out.println(p.scale());//.scale
System.out.println("Fix this sections of the tester and code!");
System.out.println("---------------------------------------------------------------");
System.out.println("Lets double the area and pull the new width and height for Rectangle o: " + o.doubleIt());//.doubleIt
System.out.println("Fix this sections of the tester and code!");
}
}
其次是我的矩形类
import java.util.*;
public class Rectangle {
//Data
private double width;
private double height;
public Rectangle(double w, double h) {
width = w;
height = h;
}
//One no-arg constructor that constructs a rectangle 1X1
public Rectangle() {
width = 1.0;
height = 1.0;
}
//One one-arg constructor that takes one double argument, and constructs a square that size
public Rectangle(double sameSides) {
width = sameSides;
height = sameSides;
}
//One two-arg constructor that takes two double arguments, and constructs a rectangle that size
//Getters and Setters
public double getWidth() {
return width;
}
public void setWidth(double width) {
this.width = width;
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
//One one-arg constructor that takes a Rectangle as an argument, and constructs as new Rectangle of identical size
public Rectangle(Rectangle rectangleDuplicate){ //calling rectangleDuplicate
Rectangle d = new Rectangle();
d.width = rectangleDuplicate.getWidth(); //set width to width of rectangleDuplicate
d.height = rectangleDuplicate.getHeight(); //set height to height of rectangleDuplicate
}
//A ".equals()" method that accepts another Rectangle as argument, and returns TRUE if the other rectangle has an area within 1% of the instance rectangle.
public boolean equals(Rectangle p){
double areaTest = (this.getArea()) / (getArea());
if (areaTest <= 1.01 && areaTest >= 0.99){
System.out.println("The area's are within 1% and thus are declared the same.");
return true;
}else{
System.out.println("These two Rectangles are not the same.");
return false;
}
}
//A ".rotate()" method that reverses height and width of the instance rectangle.
public boolean rotate(){
double newWidth = height;
double newHeight = width;
System.out.println("The new width is: " + newWidth + "\n" + "The new height is: " + newHeight);
return true;
}
//A .getArea()" method that returns the area of the rectangle.
public double getArea() {
double area = width * height;
return area;
}
//A ".getDiagonal()" method that returns the diagonal of the rectangle.
public double getDiagonal() {
double diagonal = 0;
diagonal = (width * width) + (height * height);
diagonal = Math.sqrt(diagonal);
return diagonal;
}
//A ".copy()" method that returns a rectangle of identical size.
public void copy(){
Rectangle rectangleCopy = new Rectangle(width,height);
rectangleCopy.setWidth(width); //set width to width of rectangleCopy
rectangleCopy.setHeight(height); //set height to height of rectangleCopy
}
//A ".scale()" method that accepts a single double argument, and scales the instance rectangle by that amount. For example, a 4X3 rectangle with .scale(2.0) applied to it should become 8X6 in size.
public void scale(){
System.out.println("By what scale would you like to multiply?");
Scanner scan = new Scanner(System.in);
double scale = scan.nextDouble();
width = width * scale;
height = height * scale;
}
//A ".doubleIt()" method which should double the area of the rectangle, without changing its aspect ratio (the ratio between the height and width).
public void doubleIt(){
double area = getArea() * 2;
height = area / (4*width);
width = area / (4*((height) * (4*width / area)));
}
}
答案 0 :(得分：0)
好的第一个问题我发现了：
//One one-arg constructor that takes a Rectangle as an argument, and constructs as new Rectangle of identical size
public Rectangle(Rectangle rectangleDuplicate){ //calling rectangleDuplicate
Rectangle d = new Rectangle();
d.width = rectangleDuplicate.getWidth(); //set width to width of rectangleDuplicate
d.height = rectangleDuplicate.getHeight(); //set height to height of rectangleDuplicate
}
您正在构造函数中为第二个矩形创建第三个矩形。它应该是：
//One one-arg constructor that takes a Rectangle as an argument, and constructs as new Rectangle of identical size
public Rectangle(Rectangle rectangleDuplicate){ //calling rectangleDuplicate
this.width = rectangleDuplicate.getWidth(); //set width to width of rectangleDuplicate
this.height = rectangleDuplicate.getHeight(); //set height to height of rectangleDuplicate
}
旁注：尝试始终使用此功能。使用对象的属性时，它使代码更容易阅读。如果您正在尝试更改当前对象属性，则其他人不必考虑。
第二期：
这实际上并没有改变矩形的属性，只是打印了值。
//A ".rotate()" method that reverses height and width of the instance rectangle.
public boolean rotate(){
double newWidth = height;
double newHeight = width;
System.out.println("The new width is: " + newWidth + "\n" + "The new height is: " + newHeight);
return true;
}
这使得改变：
//A ".rotate()" method that reverses height and width of the instance rectangle.
public boolean rotate(){
double newWidth = height;
double newHeight = width;
// Access the rectangle attributes and change them to the new values
this.height = newHeight;
this.width = newWidth;
System.out.println("The new width is: " + this.width + "\n" + "The new height is: " + this.height);
// Why do you need a return? Is it part of the testing?
return true;
}
第三个问题：
//A ".copy()" method that returns a rectangle of identical size.
public void copy(){
Rectangle rectangleCopy = new Rectangle(width,height);
rectangleCopy.setWidth(width); //set width to width of rectangleCopy
rectangleCopy.setHeight(height); //set height to height of rectangleCopy
}
您不会返回新矩形。它在方法运行后被丢弃。
您为这些输入创建的构造函数已经设置了高度和宽度。之后你不需要再设置它们。
应用修正：
//A ".copy()" method that returns a rectangle of identical size.
public Rectangle copy(){
Rectangle rectangleCopy = new Rectangle(width,height);
return rectangleCopy;
}
这些是我到目前为止能找到的所有问题。
编辑：我将如何测试。
例如测试copy（）
Rectangle result = i.copy();
// Check if height and width of the new rectangle have been initialized
// to the values of width and height of Rectangle i
System.out.println(result.getWidth());
System.out.println(result.getHeight());