我的 Java 方法总是返回 true 或 false，而 if else 中没有什么内容

Question

我刚刚开始学习 Java，我无法弄清楚我的方法 destroyEngine() 中做错了什么。如果你能帮助我，我将非常感激你。感谢您对我的代码的关注。我尝试更换 isReadyToDrive。创建了新变量brokenEngine。但看起来我没有称我的 int 距离正确。 我的主要。

public class CarManager {
    public static void main(String[] args) {
        Motorcycle suzuki = new Motorcycle("Suzuki GSX-R1000", 2021,16000, 600,
                " black", "diesel", false, 0);
        Motorcycle yamaha = new Motorcycle("Yamaha FZ1", 2007, 9000, 700, "orangE ",
                "gas", false, 301000);
        System.out.println(suzuki);
        System.out.println(yamaha);
    }
}

public class Motorcycle {
    String name;
    int yearOfProduction;
    int price;
    int weight;
    Color color;
    String engineType;
    boolean isReadyToDrive;
    int distance;

    public Motorcycle(String name, int yearOfProduction, int price, int weight, Color color, String engineType,
            boolean isReadyToDrive) {
        this.name = name;
        this.yearOfProduction = yearOfProduction;
        this.price = price;
        this.weight = weight;
        this.color = color;
        this.engineType = engineType;
        this.isReadyToDrive = isReadyToDrive;
    }

    public Motorcycle(String name, int yearOfProduction, int price, int weight, String color, String engineType,
            boolean isReadyToDrive, int distance) {
        this.name = name;
        this.yearOfProduction = yearOfProduction;
        this.price = price;
        this.weight = weight;
        String colorTemp = color.toUpperCase();
        this.color = Color.valueOf(colorTemp.replace(" ", ""));
        this.engineType = engineType;
        this.isReadyToDrive = destroyEngine();
        this.distance = distance;
    }

    public boolean repair() {
        isReadyToDrive = true;
        return isReadyToDrive;
    }

    public boolean brokenEngine;

    public boolean destroyEngine() {
        if (distance >= 200000) {
            brokenEngine = false;
        } else {
            brokenEngine = true;
        }
        return brokenEngine;
    }

    @Override
    public String toString() {
        return "Motorcycle [name=" + this.name + ", " + "yearOfProduction=" + yearOfProduction + ", " + "price="
                + this.price + ", " +
                " weight=" + this.weight + ", " + "color=" + this.color + ", " + " engineType=" + this.engineType + ", "
                + "isReadyToDrive=" + this.isReadyToDrive
                + ", " + "distance=" + distance + "]";
    }
}

Answer 1

在第二个构造函数中（您在

main

方法中实际使用的构造函数）

public Motorcycle(String name, int yearOfProduction, int price, int weight, String color, String engineType, boolean isReadyToDrive, int distance) {
    // previous statements omitted
    this.isReadyToDrive = destroyEngine();
    this.distance = distance;
}

destroyEngine

方法使用实例变量

distance

来决定是否返回

true

或

false

。但是，正如目前所写，

distance

实例变量仍然具有默认值 0。

您必须在调用destroyEngine

之前

给它一个值。

public Motorcycle(String name, int yearOfProduction, int price, int weight, String color, String engineType, boolean isReadyToDrive, int distance) {
    // previous statements omitted
    this.distance = distance;
    this.isReadyToDrive = destroyEngine();
}