对象正在初始化为不需要的值 [英] Object is initializing to unwanted value
问题描述
我一直在做一个简单的任务，习惯于编码。我正在设计一个ATM机，目前它由两个类组成：
-
BankAccount.cpp
- 不同类型帐户的构造函数
- 只有作为成员的余额
-
Transaction.cpp
- 对BankAccount执行方法
问题： BankAccount自动初始化为10的余额，这是不受欢迎的。例如，如果我做了支票帐户并选择存入$ 10，余额将打印出$ 20。
// BankAccount。 h
//这个类将简单地带入一个带有余额的银行帐户
//，其他类将使用一个银行帐户对象
//，例如保存/检查，并对
// balance
#ifndef BANK_ACCOUNT_H
#define BANK_ACCOUNT_H
class BankAccount {
private：
float balance;
public：
BankAccount（）;
float getBalance（）;
void makeDeposit（）;
void makeWithdrawl（）;
};
#endif
//BankAccount.cpp
#includeBankAccount.h
#include< iostream> // remove once done * not to self
using namespace std; // remove once done * note to self
BankAccount :: BankAccount（）{
balance = 0.00;
}
float BankAccount :: getBalance（）{
return balance;
}
void BankAccount :: makeDeposit（）{
cout< 你想要多少钱：;
float deposit_value;
cin>> deposit_value;
balance + = deposit_value;
}
void BankAccount :: makeWithdrawl（）{
cout< 你想要多少钱：;
float withdrawl_value;
cin>> withdrawl_value;
balance - = withdrawl_value;
}
//Transaction.h
#ifndef TRANSACTION_H
#define TRANSACTION_H
类事务{
private：
BankAccount m_bao;
public：
Transaction（BankAccount&）;
void displayOptions（）;
void printReciept（）;
};
#endif
//Transaction.cpp
#includeBankAccount.h
#includeTransaction.h
＃ include< iostream>
using namespace std;
Transaction :: Transaction（BankAccount& bao）{
m_bao = bao;
}
void Transaction :: displayOptions（）{
cout< \\\
请选择\\\
\\\
;
cout<< 1：存款
cout<< 2：Make Withdrawl\\\
;
cout<< 3：检查余额\\\
;
int选择;
cin>>选择;
switch（choice）{
case 1：
m_bao.makeDeposit（）;
break;
case 2：
m_bao.makeWithdrawl（）;
break;
case 3：
m_bao.getBalance（）;
break;
}
}
void Transaction :: printReciept（）{
cout< 当前余额现在是：< m_bao.getBalance（）+'\\\
';
}
int main（）{
BankAccount checking;
事务q（检查）;
q.displayOptions（）;
q.printReciept（）;
}
我相信答案是正确的我的眼睛前面，但我的大脑只是油炸了现在。我会继续寻找解决方案，让你们知道我的问题是否已经解决了。
好的，现在我想让客户可以选择在支票或储蓄帐户上执行交易。目前我在main（）中看起来像这样：
int main（）{
BankAccount checks（0.00）;
BankAccount Saving（0.00）;
事务c（检查）;
交易（储蓄）;
for（int i = 0; i <10; i ++）{
cout< 选择<< endl
cout<< 1.检查< endl
cout<< 2.储蓄< endl
int选择;
cin>>选择;
if（choice == 1）{
c.prompt（）;
c.printReciept（）;
}
else {
s.prompt（）;
s.printReciept（）;
}
}
}
它工作正常，但我想让这个过程更OOP-alized，如果这是有道理的）
一个选项我试图看into是一个提示函数，属于Transaction.cpp。
你的问题是这一行：
cout< 当前余额现在是：< m_bao.getBalance（）+'\\\
';
编译器看到的是：
cout<< 当前余额现在是：< （m_bao.getBalance（）+'\\\
'）;
'\\\ c $ c> 10 作为int，所以你得到这个：
'
cout< 当前余额现在是：< （m_bao.getBalance（）+ 10）;
您可能希望这样做：
cout<< 当前余额现在是：< m_bao.getBalance（）<< '\\\
';
请记住，在C ++中， + 表示添加这两个数字。
I have been working on a trivial assignment to get used to coding. I am designing an ATM machine and at the moment it is composed of 2 classes:
BankAccount.cpp
- Constructor for different types of account
- Only has balance as a member
Transaction.cpp
- Performs a method on the BankAccount (i.e make deposit, make withdrawl & get balance)
Problem: BankAccount is automatically initialized to a balance of 10 which is undesired. So for example, if I made a checking account and chose to deposit $10, balance would print out $20.
//BankAccount.h
//This class will simply take in a bank account
//with a balance, other classes will use a bank account object
//such as saving/checkings and perform operations on the
//balance
#ifndef BANK_ACCOUNT_H
#define BANK_ACCOUNT_H
class BankAccount {
private:
float balance;
public:
BankAccount ();
float getBalance ();
void makeDeposit ();
void makeWithdrawl ();
};
#endif
//BankAccount.cpp
#include "BankAccount.h"
#include <iostream> //remove once done *not to self
using namespace std; //remove once done *note to self
BankAccount::BankAccount() {
balance = 0.00;
}
float BankAccount::getBalance() {
return balance;
}
void BankAccount::makeDeposit() {
cout << "How much would you like to deposit: ";
float deposit_value;
cin >> deposit_value;
balance += deposit_value;
}
void BankAccount::makeWithdrawl() {
cout << "How much would you like to withdrawl: ";
float withdrawl_value;
cin >> withdrawl_value;
balance -= withdrawl_value;
}
//Transaction.h
#ifndef TRANSACTION_H
#define TRANSACTION_H
class Transaction {
private:
BankAccount m_bao;
public:
Transaction(BankAccount&);
void displayOptions();
void printReciept();
};
#endif
//Transaction.cpp
#include "BankAccount.h"
#include "Transaction.h"
#include <iostream>
using namespace std;
Transaction::Transaction(BankAccount& bao) {
m_bao = bao;
}
void Transaction::displayOptions() {
cout << "\nPlease make a choice\n\n";
cout << "1: Make Deposit\n";
cout << "2: Make Withdrawl\n";
cout << "3: Check Balance\n";
int choice;
cin >> choice;
switch (choice) {
case 1:
m_bao.makeDeposit();
break;
case 2:
m_bao.makeWithdrawl();
break;
case 3:
m_bao.getBalance();
break;
}
}
void Transaction::printReciept() {
cout << "Current balance is now: " << m_bao.getBalance() + '\n';
}
int main () {
BankAccount checking;
Transaction q(checking);
q.displayOptions();
q.printReciept();
}
I am sure the answer is right in front of my eyes, but my brain is just fried right now. I will continue to look for the solutions and let you guys know if my problem has been solved yet.
[EDIT]
Alright, now I am trying to make it so that the customer can choose to perform transactions on either Checking or Savings account. Currently I got it looking like this in my main():
int main () {
BankAccount checking(0.00);
BankAccount savings(0.00);
Transaction c(checking);
Transaction s(savings);
for(int i = 0; i < 10 ; i++) {
cout << "Make an option" << endl;
cout << "1. Checking " << endl;
cout << "2. Savings" << endl;
int choice;
cin >> choice;
if (choice == 1) {
c.prompt();
c.printReciept();
}
else {
s.prompt();
s.printReciept();
}
}
}
It works fine, but I would like to make this process more OOP-alized, if that makes sense :)
One option I was trying to look into was making a prompt function which would belong to Transaction.cpp. This would do everything that is done in main, except initializing the objects of course.
Your problem is this line:
cout << "Current balance is now: " << m_bao.getBalance() + '\n';
Which the compiler sees as:
cout << "Current balance is now: " << (m_bao.getBalance() + '\n');
'\n' is 10 as an int, so you get this:
cout << "Current balance is now: " << (m_bao.getBalance() + 10);
You probably meant to do this:
cout << "Current balance is now: " << m_bao.getBalance() << '\n';
Remember that in C++, + almost always means "add these two numbers".
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