Question

public class AccountDemo {

    public static void main(String [] args) {

        Account accountholder1, accountholder2, accountholder3; 

        accountholder1 = new Account(100, 10, 1000, "", "");
        accountholder1.showData();
        System.out.println(AccountDemo.numOfAccounts+" accounts opened");

        accountholder2 = new Account(200, 20, 2000, "", "");
        accountholder2.showData();
        System.out.println(AccountDemo.numOfAccounts+" accounts opened");

        accountholder3 = new Account(300, 30, 3000, "", "");
        accountholder3.showData();
        System.out.println(AccountDemo.numOfAccounts+" accounts opened");
    }
}

在numOfAccounts上，它会一直说cannot find symbol - variable numOfAccounts。

Answer 1

错误意味着Java无法找到numOfAccounts。事实上，我也找不到它 - 如果你想这样访问它，你必须将它声明为静态字段：

public class AccountDemo {
    public static int numOfAccounts = 10;
    ...
    public static void main(String [] args) {
    ...

但在此之前，请确保在静态变量和实例变量之间understand the difference。

Answer 2

您的课程中缺少numOfAccounts。看看它应该是静态的。

public class AccountDemo {

    static int numOfAccounts = 0;

    AccountDemo(){
        numOfAccounts++; //increment number of accounts
    }

    public static void main(String [] args) {

        Account accountolder1, accountHolder2, accountHolder2; 

        accountolder1 = new Account(100, 10, 1000, "", "");
        accountolder1.showData();
        System.out.println(AccountDemo.numOfAccounts+" accounts opened");

        accountolder2 = new Account(200, 20, 2000, "", "");
        accountolder2.showData();
        System.out.println(AccountDemo.numOfAccounts+" accounts opened");

        accountolder3 = new Account(300, 30, 3000, "", "");
        accountolder3.showData();
        System.out.println(AccountDemo.numOfAccounts+" accounts opened");
    }
}

找不到符号（numOfAccounts）

2 个答案: