重载的java方法

Question

  //*******************************************************
// FlexibleAccount.java
//
// A bank account class with methods to deposit to, withdraw from,
// change the name on, and get a String representation
// of the account.
//*******************************************************
import java.util.Random;
public class FlexibleAccount
{
  private double balance;
  private String name;
  private long acctNum;

  //----------------------------------------------
  //Constructor -- initializes balance, owner, and account number
  //----------------------------------------------
  public FlexibleAccount(double initBal, String owner, long number)
  {
    balance = initBal;
    name = owner;
    acctNum = number;
  }

  public FlexibleAccount(double initBal, String owner, double number)
  {
    Random generator = new Random();
     balance = initBal;
    name = owner;
     number=generator.nextDouble();
     this.acctNum= number;
    }

    public FlexibleAccount(String owner)
    {
     balance = 0;
     name=owner;
     Random generator = new Random();
     number=generator.nextDouble();
     this.acctNum= number;
     }
  //----------------------------------------------
  // Checks to see if balance is sufficient for withdrawal.
  // If so, decrements balance by amount; if not, prints message.
  //----------------------------------------------
  public void withdraw(double amount)
  {
    if (balance >= amount)
       balance -= amount;
    else
       System.out.println("Insufficient funds");
  }

  public void withdraw(double amount,int fee)

  {
   if(balance>=amount)
    balance-= amount+fee;
    else
        System.out.println("Insufficient funds");
    }   

  //----------------------------------------------
  // Adds deposit amount to balance.
  //----------------------------------------------
  public void deposit(double amount)
  {
    balance += amount;
  }

  //----------------------------------------------
  // Returns balance.
  //----------------------------------------------
  public double getBalance()
  {
    return balance;
  }


  //----------------------------------------------
  // Returns a string containing the name, account number, and balance.
  //----------------------------------------------
  public String toString()
  {
    return "Name: " + name + 
"\nAccount Number: " + acctNum +
"\nBalance: " + balance; 
  }
}

这就是我所拥有的，我正试图使FlexibleAccount过载3倍，如下所示

1. public FlexibleAccount（双初始值、字符串所有者、长编号）–根据指定初始化余额、所有者和帐号
2. public FlexibleAccount（double initBal，String owner）–根据指定初始化余额和所有者；随机生成帐号
3. public FlexibleAccount（字符串所有者）–根据指定初始化所有者；将初始余额设置为0并随机生成账号

当我编译时，我得到了这些错误

 FlexibleAccount.java:31: possible loss of precision
    found   : double
    required: long
         this.acctNum= number;
                       ^
    FlexibleAccount.java:39: cannot find symbol
    symbol  : variable number
    location: class FlexibleAccount
         number=generator.nextDouble();
         ^
    FlexibleAccount.java:40: cannot find symbol
    symbol  : variable number
    location: class FlexibleAccount
         this.acctNum= number;
                   ^

我如何解决这个问题，这是过载的正确方法吗

Answer 1

就像前面的问题一样-在public FlexibleAccount(String owner)中写入acctNum = number;时，没有这样的变量number：

public FlexibleAccount(String owner)
    {
     balance = 0;
     name=owner;
     Random generator = new Random();
     number=generator.nextDouble();        << number is not declared
     this.acctNum= number;
     }

编辑： 这是您的第二个构造函数：

 public FlexibleAccount(double initBal, String owner, double number)
  {
    Random generator = new Random();
     balance = initBal;
    name = owner;
     number=generator.nextDouble();
     this.acctNum= number;
    }

出于某种原因，您声明它有3个参数，尽管您编写了您希望它只接收2个参数-

public FlexibleAccount (double initBal, String owner) – initializes the balance and owner as specified; randomly generates the account number.

我猜你想要一个可变的数字。。。应该是这样的：

 public FlexibleAccount(double initBal, String owner)
      {
        Random generator = new Random();
         balance = initBal;
        name = owner;
         this.acctNum= generator.nextLong();
        }

正如你在上一篇文章中所说的。问题这是一个家庭作业，所以我不会再补充了。阅读到目前为止你得到的答案和评论，并进行整理