在java中使用toString可以'；找不到符号错误？

我一直在尝试将getter和setter与toString一起使用，但我很难看到我的代码有什么问题。我不确定问题到底出在哪里。 那么，我应该有一个主管道吗？我不确定在这种情况下是否需要这样做

还有，有没有什么方法可以更好地格式化“矩形（x，x）”它现在看起来有点奇怪

public class Rectangle {
// DO NOT MODIFY THE INSTANCE VARIABLES
// begin instance variables
private int width;
private int height;
// end instance variables

// TODO - write your code below this comment.
// You need to do the following:
//
// 1.) Define a constructor which takes two ints
//     representing the width and height, respectively.
//     The constructor should set its instance variables
//     equal to these values.
//
// 2.) Define a "getter" named getWidth, which returns
//     the width of the rectangle.
//
// 3.) Define a "getter" named getHeight, which returns
//     the height of the rectangle.
//
// 4.) Define a "setter" named setWidth, which takes
//     the new width of the rectangle and sets the
//     rectangle's width to that value.
//
// 5.) Define a "setter" named setHeight, which
//     takes the new height of the rectangle and sets
//     the rectangle's height to that value
//
// 6.) Define a toString method, which returns
//     a String representation of the rectangle.
//     As an example, if the width of the rectangle is
//     3 and the height of the rectangle is 4, this should
//     return the String:
//
//     "Rectangle(3, 4)"
//
public Rectangle(int rectWidth, int rectHeight) {
    rectWidth = width;
    rectHeight = height;
}
public int getWidth() {
    return width;
}
public int getHeight() {
    return height;
}
public void setWidth(int rectWidth) {
    width = rectWidth;
}
public void setheight(int rectHeight) {
    height = rectHeight;
}
public String toString() {
    return s;
}
    public static void main(String[] args) {
    Rectangle s = new Rectangle("Rectangle"+"("+rectWidth+", 
"+rectHeight+")");
    System.out.println(s);
    }
}

---

有两点：您的构造函数不正确：

您需要为正在创建的“this”对象设置实例变量，并且必须使用正确的参数调用构造函数。 应该使用ToString来获取矩形的这个特定实例的字符串表示形式。试试这个：

public class Rectangle {
    // DO NOT MODIFY THE INSTANCE VARIABLES
    // begin instance variables
    private int width;
    private int height;
    // end instance variables

    // TODO - write your code below this comment.
    // You need to do the following:
    //
    // 1.) Define a constructor which takes two ints
    //     representing the width and height, respectively.
    //     The constructor should set its instance variables
    //     equal to these values.
    //
    // 2.) Define a "getter" named getWidth, which returns
    //     the width of the rectangle.
    //
    // 3.) Define a "getter" named getHeight, which returns
    //     the height of the rectangle.
    //
    // 4.) Define a "setter" named setWidth, which takes
    //     the new width of the rectangle and sets the
    //     rectangle's width to that value.
    //
    // 5.) Define a "setter" named setHeight, which
    //     takes the new height of the rectangle and sets
    //     the rectangle's height to that value
    //
    // 6.) Define a toString method, which returns
    //     a String representation of the rectangle.
    //     As an example, if the width of the rectangle is
    //     3 and the height of the rectangle is 4, this should
    //     return the String:
    //
    //     "Rectangle(3, 4)"
    //
    public Rectangle(int rectWidth, int rectHeight) {
        // "this" refers to the instance of Rectangle you are creating
        // so this objects width and height are set to the values passed into the constructor...
        this.width = rectWidth;
        this.height = rectHeight;
    }
    public int getWidth() {
        return width;
    }
    public int getHeight() {
        return height;
    }
    public void setWidth(int rectWidth) {
        width = rectWidth;
    }
    public void setheight(int rectHeight) {
        height = rectHeight;
    }
    public String toString() {
        // the toString returns a string representation for "this" object
        return "Rectangle(" + this.width + "," + this.height + ")";
    }
    public static void main(String[] args) {
        Rectangle s = new Rectangle(5,4);
                System.out.println(s);
    }
}

---

但请把它作为一个最小的例子。评论等不相关。现在，您似乎正在尝试调用一个不存在的

矩形（字符串）

构造函数，使用的变量

rectWidth

和

rectHeight

不在范围内。现在还不清楚您希望它如何工作。我怀疑

main

方法的第一行应该是

rectangles=newrectangle（3,4）toString（）

方法试图返回

s

，它不是类中的字段……此外，我认为你的构造函数没有做它应该做的事情。您希望将参数指定给属性，而不是反过来。使用此选项进行更改。宽度=矩形宽度；this.height=矩形高度；最好将主函数放在一个单独的类中。此外，您的toString应该返回您当前在主函数中拥有的“矩形”+（“+rectWidth+”，“+rectHeight+”）部分