了解对象以及如何将分配的变量封装到私有变量

Question

我正在尝试用Java编写一个程序，该程序显示茶的名称，类型，克，浸泡和双重浸泡时间，以练习学习类/对象/方法。

我遇到了错误，希望有人能帮助阐明一些问题。

public class Tea {
    private String Name;
    private String Type;
    private int GramsPerCup;
    private int SteepingMinutes;
    public Tea()//default constructor, takes no args, must be same name as class
    {
    }
    public Tea(String Name, String Type, int GramsPerCup, int SteepingMinutes)//constructor that takes arguments
    {
        Name = Name;
        Type = Type;
        GramsPerCup = GramsPerCup;
        SteepingMinutes = SteepingMinutes;
    }
    public void DoubleSteep() {
        int TeaDoubleSteep = SteepingMinutes * 2;
    }
    public String PrintDetails() {
        return "Name: " + Name + "n" + "Type: " + Type + "/n" + "Grams Per Cup: " + GramsPerCup + "n" + "Steeping Time in Minutes: " + SteepingMinutes + "n" + "For dark brew, steep: " + DoubleSteep + " minutes";
    }
}
public class Main {
    public static void Main(String[] args) {
        Tea tea1 = new Tea("Earl Grey", "Black", 3, 5);
        tea1.DoubleSteep();
        System.out.println(tea1.PrintDetails());
    }
}

请善待，我对此很陌生，谢谢！:)

Answer 1

只是一个提示！

您的代码中有多个错误：

第一：

要创建一个新对象，您必须使用new然后space然后是类的名称：

Tea tea1 = newTea("Earl Grey", "Black", 3, 5);//wrong
Tea tea1 = new Tea("Earl Grey", "Black", 3, 5);//correct
//---------^^^^------------------------------------------Note that

第二：

要调用另一个类中的方法，您必须使用 className.methodName() ，而不是：

System.out.println(tea1, PrintDetails());
//---------------------^^--------To call a method in another class you have to use dot(.)

请改用这个：

System.out.println(tea1.PrintDetails());

第三：

您在构造函数中分配了错误的值：

public Tea(String Name, String Type, int GramsPerCup, int SteepingMinutes)
{
    Name = TeaName;
    //----^^^^^^^^--------Thie name is not exist in your method signature
    //same to the others
}

您必须使用：

this.Name = Name;