多个构造函数类Setter C ++

Question

所以，我刚才有一个关于我的教授对我们所做的一个项目的反馈的问题。我不太理解她对第二个构造函数中的setter函数的意思。以下是她所说的：

  

下次确保在尝试实验室之前完成阅读和准备工作。仔细阅读作业。

     

问题是重载的构造函数（构造函数＃2）应该调用setter函数。

     

未测试重载的构造函数（构造函数＃2）。使用重载的构造函数创建一个对象，如下所示：Inventory itemTwo（666,3，.99）;

     

漂亮的课程，漂亮的主程序和编码风格。

这就是问题：

Problem

最后，这是我的代码：

#include <iostream>
#include <iomanip>
using namespace std;

class Inventory
{
	private:
		int itemNumber;			//Private Class Members
		int quanity;
		double cost;
	public:
		Inventory();			//Public Member Functions
		Inventory(int i, int q, double c);
		void setItemNumber(int);
		void setQuanity(int);
		void setCost(double);
		int getItemNumber() const;
		int getQuanity() const;
		double getCost() const;
		double getTotalCost() const;
};

int main()
{
	int itemNum;
	int qty;
	double price;	
	Inventory itemOne;			//Declares itemOne and itemTwo being an Inventory class objects
	Inventory itemTwo;
	
/****************************************************************************/
	
	cout << "Please Enter Data For Item One\n";					//Data entry for Item One
	cout << "Enter item number: ";
	cin >> itemNum;
		
	while (itemNum < 0)											//Safegaurds for data
	{
		cout << "Please enter a non-negative item number: ";
		cin >> itemNum;		
	}
	
	cout << "Enter quanity: ";
	cin >> qty;
	
	while (qty < 0)
	{
		cout << "Please enter a non-negative quanity number: ";
		cin >> qty;
	}
	
	cout << "Enter price: ";
	cin >> price;
	
	while (price < 0)
	{
		cout << "Please enter a non-negative price: ";
		cin >> price;
	}
		
	itemOne.setItemNumber(itemNum);			//Passes All Data To Correct Functions
	itemOne.setQuanity(qty);
	itemOne.setCost(price);	
	cout << endl;										//Formatting
	
/****************************************************************************/	

	cout << "Please Enter Data For Item Two\n";				//Data Entry for Item Two
	cout << "Enter item number: ";
	cin >> itemNum;
		
	while (itemNum < 0)
	{
		cout << "Please enter a non-negative item number: ";
		cin >> itemNum;		
	}
	
	cout << "Enter quanity: ";
	cin >> qty;
	
	while (qty < 0)
	{
		cout << "Please enter a non-negative quanity number: ";
		cin >> qty;
	}
	
	cout << "Enter price: ";
	cin >> price;
	
	while (price < 0)
	{
		cout << "Please enter a non-negative price: ";
		cin >> price;
	}
	
	itemTwo.setItemNumber(itemNum);			//Passes All Data To Correct Functions
	itemTwo.setQuanity(qty);
	itemTwo.setCost(price);
	cout << endl;										//Formatting
	
/****************************************************************************/	

	
	cout << fixed << showpoint << setprecision(2);

	//All input displayed here
	cout << "Here's the data you entered for item one:\n";
	cout << "Item Number: " << "		" << itemOne.getItemNumber() << endl;
	cout << "Item Quanity: " << "		" << itemOne.getQuanity() << endl;
	cout << "Item Cost: " << "		" << "$" << itemOne.getCost() << endl;
	cout << "Item Total Cost: " << "	" <<"$" << itemOne.getTotalCost() << endl << endl;
	
	cout << "Here's the data you entered for item two:\n";
	cout << "Item Number: " << "		" << itemTwo.getItemNumber() << endl;
	cout << "Item Quanity: " << "		" << itemTwo.getQuanity() << endl;
	cout << "Item Cost: " << "		" << "$" << itemTwo.getCost() << endl;
	cout << "Item Total Cost: " << "	" <<"$" << itemTwo.getTotalCost() << endl;
	
	return 0;
}

Inventory::Inventory()							//Default Constructor
{
	itemNumber = 0;
	quanity = 0; 
	cost = 0;
}

Inventory::Inventory(int i, int q, double c)	//Constructor #2
{
	itemNumber = i;
	quanity = q; 
	cost = c;
}

void Inventory::setItemNumber(int i)			//Re-Evaluates For a Negative Number and
{												//Passes User's Entered Data to the Private class
	if (i >= 0)
		itemNumber = i;
	else
		itemNumber = 0;
}

void Inventory::setQuanity(int q)				//Re-Evaluates For a Negative Number and
{												//Passes User's Entered Data to the Private class
	if (q >= 0)
		quanity = q;
	else
		quanity = 0;
}

void Inventory::setCost(double c)				////Re-Evaluates For a Negative Number and
{												//Passes User's Entered Data to the Private class
	if (c >= 0)
		cost = c;
	else
		cost = 0;
}

int Inventory::getItemNumber() const			//All 'Getter' Functions to Display Object's Data
{												//Whilst Keeping Data Integrity With 'const'
	return itemNumber;
}

int Inventory::getQuanity() const
{
	return quanity;
}

double Inventory::getCost() const
{
	return cost;
}

double Inventory::getTotalCost() const			//Calculates Total Cost and Returns
{
	return cost * quanity;
}

/*
-----------------------------------------------------
Please Enter Data For Item One
Enter item number: 1303
Enter quanity: 10
Enter price: 2.50

Please Enter Data For Item Two
Enter item number: 5676
Enter quanity: 54
Enter price: 5.65

Here's the data you entered for item one:
Item Number:            1303
Item Quanity:           10
Item Cost:              $2.50
Item Total Cost:        $25.00

Here's the data you entered for item two:
Item Number:            5676
Item Quanity:           54
Item Cost:              $5.65
Item Total Cost:        $305.10
-----------------------------------------------------
Please Enter Data For Item One
Enter item number: 7456
Enter quanity: 10
Enter price: 10.9

Please Enter Data For Item Two
Enter item number: 0293
Enter quanity: 5
Enter price: 109.23

Here's the data you entered for item one:
Item Number:            7456
Item Quanity:           10
Item Cost:              $10.90
Item Total Cost:        $109.00

Here's the data you entered for item two:
Item Number:            293
Item Quanity:           5
Item Cost:              $109.23
Item Total Cost:        $546.15
-----------------------------------------------------
*/

Answer 1

您的教授可能意味着您应该在构造函数中调用setter函数，而不是直接设置值：

Inventory::Inventory(int i, int q, double c)    //Constructor #2
{
    setItemNumber(i);
    setQuantity(q); 
    setCost(c);
}

Answer 2

她是对的。您正在接受用户输入，因此您必须使用您的setter进行验证，您出于某种原因创建了它们。

Inventory::Inventory(int i, int q, double c)    //Constructor #2
{
    setItemNumber(i);
    setQuantity(q); 
    setCost(c);
}