如何将音量从getVolume调用到isBigbox方法中？

Question

如何将volume从getVolume调用到isBigbox方法中，以编写检查Box vlomue是否大于或等于500的If语句？

正如你在标题中读到的，我试图在isBigbox方法中使用getVolume方法中的卷来检查卷是否小于或等于500，它将打印一条语句，说明它的大盒子，否则它将显示它是一个小盒子

public class Box {

    private double length;
    private double width;
    private double height;
    private String color;

    public Box(double length, double width, double height, String color) {
        this.length = length;
        this.width = width;
        this.height = height;
        this.color = color;
    }

    // Overload constructor 1
    public Box() {
        this(1, 1, 1, "without color");
    }

    // Overload constructor 2
    public Box(double length, double width, double height) {
        this(1, 2, 3, "blue");
    }

    // Overload constructor 3
    public Box(double width, double height, String color) {
        this(5, 5, 8, "red");
    }

    // Standard getters and setters omitted for brevity

    public void getVolume(double volume) {
        volume = this.height * this.width * this.height;
        System.out.println("The Volume of the box is:" + volume);
    }
      
    public void isBigBox(Box b) {
        //
    }
}

Answer 1

调用方法getVolume，但它不返回任何内容（void）。您应该拆分这些方法，然后直接调用它们：

public double getVolume() {
    return this.height * this.width * this.length;      
}

public void printVolume() {
    System.out.println("The Volume of the box is:" + this.getVolume());      
}

在isBigBox中，您可以简单地检查音量：

public boolean isBigBox() {
    return this.getVolume() > 500;
}

Answer 2

您将需要在类Box中创建称为卷的变量并使构造函数计算卷。你需要这样的东西：

 public class Box {
    
    private double length;
    private double width;
    private double height;
    private String color;
    //
    private double volume:    

    public Box(double length, double width, double height,String color){
        this.length=length;
        this.width=width;
        this.height=height;
        this.color=color;
        //
        this.volume = length*width*height;
    }
  
    // 
    public double getVolume() {
        return volume;
    }
    // 
    public boolean isBigBox(){
        return (volume >= 500); 
    }
}