我正在尝试用c ++创建一个对象数组。
我正在我公司类的构造函数中创建一个employee对象：
employee obj(int tempIdNum, double tempBase, double tempSales, double tempRate);
emp[tempcount]=obj; (this doesn't work?)
Emp是此处定义的数组的名称，位于我公司的h文件中。
Employee emp[4];
using namespace std;
//----------------------------------------
//Name: default constructor
//Purpose: create a new object with attributes set to zero
//Parameters: none
//Returns: none
//----------------------------------------
Commission::Commission()
{
//cout << "In default constructor of Commission class" << endl;
idNum = 0;
base = 0.0;
rate = 0.0;
sales = 0.0;
}
//----------------------------------------
//Name: initializing constructor
//Purpose: initialize all attributes
//Parameters:
// idNum - new value for id Num
// base - new value for base amount
// sales - new value for sales amount
// rate - new value for rate fraction
//Returns: none
//----------------------------------------
Commission::Commission(int idNum, double base, double sales, double rate)
{
//cout << "In initializing constructor of Commission class" << endl;
this->idNum = idNum;
this->base = base;
this->sales = sales;
this->rate = rate;
}
//----------------------------------------
//Name: copy constructor
//Purpose: constructor a new object from an existing object
//Parameters:
// emp - current employee object
//Returns: none
//----------------------------------------
Commission::Commission(const Commission& emp)
{
//cout << "In copy constructor of Commission class" << endl;
idNum = emp.idNum;
base = emp.base;
sales = emp.sales;
rate = emp.rate;
}
//----------------------------------------
//Name: operator=
//Purpose: The copy assignment method copies the rhs object
// into the lhs object
//Parameters:
// rhs - object on the right hand side of the = sign
//Returns: nothing
//----------------------------------------
void Commission::operator=(const Commission& rhs)
{
//cout << "In copy assignment of Commission class" << endl;
idNum = rhs.idNum;
base = rhs.base;
sales = rhs.sales;
rate = rhs.rate;
}
//----------------------------------------
//Name: destructor
//Purpose: destruct object and print id num
//Parameters: none
//Returns:
//----------------------------------------
Commission::~Commission()
{
//cout << "In destructor of Commission class for id num: " << idNum << endl;
}
//----------------------------------------
//Name: setIdNum
//Purpose: set id num to a new value
//Parameters:
// newIdNum - new value for id num
//Returns: true if new id num is between 0 and 999, inclusively
// otherwise false
//----------------------------------------
bool Commission::setIdNum(int newIdNum)
{
if (newIdNum >= 0 && newIdNum <= 999)
{
idNum = newIdNum;
return true;
}
else
return false;
}
//----------------------------------------
//Name: setBase
//Purpose: set base to a new value
//Parameters:
// newBase - new value for base
//Returns: true if new base is greater zero; otherwise false
//----------------------------------------
bool Commission::setBase(double newBase)
{
if (newBase > 0.0)
{
base = newBase;
return true;
}
else
return false;
}
//----------------------------------------
//Name: setRate
//Purpose: set the commission rate
//Parameters:
// newRate - new commission rate as a percentage
//Returns: true if rate greater than zero and less than or equal to 0.20
//----------------------------------------
bool Commission::setRate(double newRate)
{
if (newRate > 0.0 && newRate <= 0.20)
{
rate = newRate;
return true;
}
else
return false;
}
//----------------------------------------
//Name: setSales
//Purpose: set sales to a new amount
//Parameters:
// newSales - new amount of sales
//Returns: true if sales is greater than or equal to zero; otherwise false
//----------------------------------------
bool Commission::setSales(double newSales)
{
if (newSales >= 0.0)
{
sales = newSales;
return true;
}
else
return false;
}
//----------------------------------------
//Name: getIdNum
//Purpose: get the current id num
//Parameters: none
//Returns: current id num
//----------------------------------------
int Commission::getIdNum()
{
return idNum;
}
//----------------------------------------
//Name: getBase
//Purpose: get the current base amount of salary
//Parameters: none
//Returns: current base salary
//----------------------------------------
double Commission::getBase()
{
return base;
}
//----------------------------------------
//Name: getRate
//Purpose: get the current commission rate as fraction
//Parameters: none
//Returns: current commission rate
//----------------------------------------
double Commission::getRate()
{
return rate;
}
//----------------------------------------
//Name: getSales
//Purpose: get current amount of sales
//Parameters: none
//Returns: current amount of sales
//----------------------------------------
double Commission::getSales()
{
return sales;
}
//----------------------------------------
//Name: calcSalary
//Purpose: calculate commission as base + sales x commission rate
//Parameters: none
//Returns: amount of commission
//----------------------------------------
double Commission::calcSalary()
{
return (base + sales * rate);
}
and here is its .h
#include <string>
using namespace std;
#ifndef Commission_H
#define Commission_H
class Commission
{
private:
int idNum; //id number of employee
double base; //base salary
double rate; //rate of commission as fraction
double sales; //sales on which commission rate applies
public:
//constructors
Commission(); //default constructor
Commission(int idNum, double base, double sales, double rate); //constructor with idNum
Commission(const Commission& orig); //copy constructor
//destructor
~Commission( );
//copy assignment
void operator=(const Commission& rhs);
//mutators
bool setIdNum(int idNum); //set id num
bool setBase(double base); //set base salary
bool setRate(double rate); //set rate of commission
bool setSales(double sales); //set amount of sales for commission
//accessors
int getIdNum(); //get id num;
double getBase(); //get base salary
double getRate(); //get commission rate
double getSales(); //get sales for commission
//calculate salary
double calcSalary(); //calculate commission
};
#endif
答案 0 :(得分：1)
如错误消息所述：employee类必须具有可访问的operator=才能编译此代码。正如您可能已经知道的那样，如果您自己不提供复制赋值运算符，编译器将声明它。
至于错误的原因，我怀疑employee有const个数据成员或其他任何使隐式定义的运算符格式错误的结果（12.8 / 12）：
程序不正常 如果隐式定义了复制赋值运算符的类具有：
const类型的非静态数据成员，或- 引用类型的非静态数据成员，或
- 具有无法访问的复制赋值运算符的类类型（或其数组）的非静态数据成员，或
- 具有无法访问的复制赋值运算符的基类。
答案 1 :(得分：0)
我假设您将数组声明为
employee emp[MAX];
所以当你
employee obj(int tempIdNum, double tempBase, double tempSales, double tempRate);
emp[tempcount] = obj
这是你做的：
obj emp[tempcount]对象（想想赋值运算符）。关于这一部分，我不完全确定，但是当你做的时候
employee emp[MAX];
您实际创建了MAX个员工对象（全部使用默认构造函数）。
答案 2 :(得分：0)
施工似乎错了。删除类型说明符：
Employee obj(tempIdNum, tempBase, tempSales, tempRate);
或尝试：
emp[tempcount]=Employee(tempIdNum, tempBase, tempSales, tempRate);
答案 3 :(得分：0)
也许，你需要实现一个“operator =”构造函数，如下所示：
Employee& Employee::operator =(const Employee& otheremp)
{
// to be done ...
}
答案 4 :(得分：0)
最后但并非最不重要。试试这个：
employee array[100];
employee e(1,1.1,1.5,2.5);
array[0] = e;
应该有效
答案 5 :(得分：0)
答案 6 :(得分：-2)
制作对象数组并不好。更好的方法是创建一个指向对象的数组。
employee ** array;
array = new employee[array_count]; // create an array of object pointers
for(int i=0; i<array_count; i++)
{
array[i] = new employee( . . . your constructor parameters . . .);
OR
array[i] = *(anExistingEmployeeObject);
}
请不要忘记安全删除数组：
for(int i=0; i<array_count; i++) delete array[i];
delete array;