预期的类找到了对象

Question

ArrayList transactions = new ArrayList<Transaction>();

public void printTransactions() {
    for(Transaction t: transactions)
        System.out.println("Transaction Type: " + t.getType() +
                           "\nDescription: " + t.getDescription() +
                           "\nAmount: " + t.getAmount() +
                           "\nNew Balance: " + t.getBalance() + 
                           "\nDate: " + t.getDate());
}

我是Java的新手,我花了很多时间试图找出这个错误.在我的printTransactions()方法中,它表示从for循环行开始"错误:不兼容的类型需要事务找到对象"

我所尝试的是投射t到一个事务类,Transaction(t).getType()但这也没有帮助.

Answer 1

您在transactions声明中缺少泛型类型.试试这个

ArrayList<Transaction> transactions = new ArrayList<Transaction>();