java - 不断收到错误消息“找不到符号 - 构造函数帐户(int，double)

Question

修改类帐户(附在 Blackboard 中)以提供• 整数类即时变量 accountNum 作为类号(不要忘记您需要更改构造函数)。• 一种称为借记的方法，可从帐户中提取资金。确保这件事借方金额不超过账户余额。如果确实如此，则余额应保持不变，该方法应打印一条消息表明“借方金额超出账户余额”。• 在方法 getBalance() 中，添加一行以打印帐号并帐户余额，然后在测试程序中，您只需键入，account1.getBalance();而不是 printf 语句。AccountTest 文件已被修改以测试您的新 Accountclass，因此您不需要改变它。

这是我的帐户类代码

public class Account
{
    private double balance;
    public int accountNum;
    public int Account;
    public Account(double initialBalance, int accountN)
    {
        if ( initialBalance > 0.0 )
            balance = initialBalance;
            accountNum=accountN;
    }

    public void credit( double amount )
    {
        balance = balance + amount;
    }

    public void debit(double amount)
    {
        if (amount>=balance)
            System.out.println("Debit amount exceeded account balance."); 
        else
            balance-=amount;
    }

    public String getBalance()
    {
        return balance+" "+accountNum;
    } 
}

这是 AccountTest 类的代码

import java.util.Scanner;

public class AccountTest
{
    // main method begins execution of Java application
    public static void main( String args[] ) 
    {
        Account account1 = new Account( 1, 50.00 ); // create Account object
        Account account2 = new Account( 2, -7.53 ); // create Account object

        // display initial balance of each object
        account1.getBalance();
        account2.getBalance();

        // create Scanner to obtain input from command window
        Scanner input = new Scanner( System.in );
        double depositAmount; // deposit amount read from user

        System.out.print( "Enter deposit amount for account2: " );
        depositAmount = input.nextDouble(); // obtain user input
        System.out.printf( "\nadding %.2f from account1 balance\n", depositAmount );
        account2.credit( depositAmount ); // add amount to account1

        // display balances
        account1.getBalance();
        account2.getBalance();

        // create Scanner to obtain input from command window
        input = new Scanner( System.in );
        double withdrawalAmount; // withdrawal amount read from user

        System.out.print( "Enter withdrawal amount for account1: " ); 
        withdrawalAmount = input.nextDouble(); // obtain user input
        System.out.printf( "\nsubtracting %.2f from account2 balance\n", withdrawalAmount );
        account1.debit( withdrawalAmount ); // subtract amount from account2

        // display balances
        account1.getBalance();
        account2.getBalance();
    } // end main
} // end class AccountTest

我无法弄清楚缺少什么，请帮忙，非常感谢。

Answer 1

您只需让您的 Account 构造函数按顺序接受 double 和 int。

所以在你的主要方法之后你有

Account account1 = new Account( 1, 50.00 );
Account account2 = new Account( 2, -7.53 );

什么时候应该

Account account1 = new Account(50.00, 1);
Account account2 = new Account(-7.53, 2);

只有当您传递的值与方法声明中的值完全相同时，Java 中的所有方法和构造函数才会起作用。一般来说，每次您看到“找不到符号”错误时，都是这个问题。