java - 难以理解方法和教授的指导

Question

好的，我的教授已经指定了

"Your ship's refuel method should take an integer amount and not return anything. When a ship is asked to refuel, its current fuel level is increased by the additional fuel amount specified and it reports that it was refueled: "Enterprise added 5 to its fuel reserves." However, if a ship is asked to refuel with an additional fuel amount less than one, the ship's fuel level remains unchanged and it reports why it wasn't refueled: "Enterprise cannot refuel with -5 fuel."

这就是我所拥有的

    public refuel(int Fuels)
    {
        if(Fuels < 1)
        {
            Fuels = fuel;
            "Challenger cannot refuel with " + fuel + " fuel.";
        }
        else
        {
            fuel += Fuels; 
//return (name + "added " + Fuels + " to its fuel reserves");
        }
    }

运行此代码时出现编译错误:

invalid method declaration; return type required public refuel(int Fuels)

当我输入时

public String refuel(int Fuels)  and insert the return statement, the method it compiles.

Answer 1

对于您不想返回任何内容的方法/函数，您应该使用 void 返回类型。至于说明，您的教授希望您在必要时添加燃料并向用户输出正确的消息。您的代码基本上是正确的，只有一些小的语法错误。