java - 如何在处理过程中将类添加到数组列表中？

Question

每当我尝试添加 country进入我的ArrayList<country>我不断收到此错误:unexpected token: (它突出显示了我的 countries.add线。我不确定为什么会发生这种情况。

class country  {
    private int mland, mwaters; //mtotalborders;
    private String mcenter;

    country(int earth, int aqua, String yn)  {
        mland = earth;
        mwaters = aqua;
        mcenter = yn;
    }
    public int getLand()  {
        return mland;
    }
    public int getWaters()  {
        return mwaters;
    }
    public int getTotalBorders()  {
        return mland+mwaters;
    }
    public String getCenter()  {
        return mcenter;
    }
}

country Turkey = new country(16, 7, "No");
country France = new country(22, 4, "No");
country England = new country(17, 9, "No");
country Germany = new country(26, 4, "Yes");
country Austria = new country(28, 1, "Yes");
country Italy = new country(17, 8, "Yes");
country Russia = new country(23, 3, "No");
ArrayList<country> countries = new ArrayList<country>();
countries.add(Turkey);

Answer 1

您需要将代码放入一个方法中 - 您可能想要使用 main 方法 - 见下文。

    ......

    public String getCenter()  {
        return mcenter;
    }

    public static void main(String[] args){
        country Turkey = new country(16, 7, "No");
        country France = new country(22, 4, "No");
        country England = new country(17, 9, "No");
        country Germany = new country(26, 4, "Yes");
        country Austria = new country(28, 1, "Yes");
        country Italy = new country(17, 8, "Yes");
        country Russia = new country(23, 3, "No");
        ArrayList<country> countries = new ArrayList<country>();
        countries.add(Turkey);
    }
}

<小时/>

注意:正确的约定是类名称大写，变量名称小写。

这将要求您更改代码中的类名称 - 见下文。

class Country  {
    private int mland, mwaters; //mtotalborders;
    private String mcenter;

    Country(int earth, int aqua, String yn)  {
        ......

此外，每当您引用Class名称时。例如。

Country turkey = new Country(16, 7, "No");