Question

我在为类创建对象时遇到问题，尝试使用已定义的数据成员创建类对象时出错。

// class header for employee
#pragma once
#include <string>
#include <iostream>
class Employee
{
private:
    std::string name;
    int empnum;
    std::string address;
    std::string phone;
    double hourwage;
    double hoursworked;
public:
    Employee(void);
    Employee(int, std::string , std::string, std::string, double, double);
    double gethourwage () const;
    double gethoursworked () const;
    double printcheck () const;
    std::string getphone() const;
    std::string getname() const;
    std::string getaddress() const;
};
// end of header

// employee class.cpp
#include "Employee.h"
#include <string>
#include <iostream>

Employee::Employee(void)
{
    int empnum = 0;
    double hourwage = 0.0;
    double hoursworked = 0.0;
}
Employee::Employee(int num, std::string nme, std::string addres, std::string phon, double hourpay, double hrswrked)
{
    num = empnum;
    nme = name;
    addres = address;
    phon = phone;
    hourpay = hourwage;
    hrswrked = hoursworked;
}

double Employee::gethourwage() const
{
    return hourwage;
}
double Employee::gethoursworked() const
{
    return hoursworked;
}
double Employee::printcheck() const
{
    double pay = 0.0;
    double hrspay = hourwage;
    double hrswork = hoursworked;
    return hoursworked;

}
// end of employee.cpp
// main
#include <iostream>
#include <algorithm>
#include <numeric>
#include <vector>
#include <iterator>
#include <string>
#include "Employee.h"

using namespace std;
int main( )
{
    int num1 = 10210;
    double hourwage = 20.2;
    double hourworked = 32.3;
    string steve;
    Employee emp(num1, steve, 58s200w, 90210, hourwage, hourworked);
    cout << "" << emp.getaddress();

    system("PAUSE");
    return 0;
} // end of main

“Employee emp（num1，steve，58s200w，90210，hourwage，hourworked）;”最底层的是我遇到的问题。我不确定我是以错误的顺序输入它还是别的。

提前感谢您的帮助。

Answer 1

您应该用双引号输入字符串：

Employee emp(num1, "steve", "58s200w", "90210", hourwage, hourworked);

修改1（尝试解释const char *和std::string之间的区别，正如@Alex建议的那样）

上面代码段中的文字字符串属于const char *类型，它是从C语言继承的低级实体。 const char *是内存区域的指针，其中包含const char类型的连续值。

std::string是C风格字符串的高级包装器，旨在提供更多“用户友好”的API并解决C风格字符串的一些问题（例如，动态分配和自动内存清理）。 / p>

因为std::string类有一个带const char *参数的构造函数，传递给Employee构造函数的文字字符串会隐式转换为std::string的

Answer 2

您的Employee类构造函数是

Employee::Employee(int num, std::string nme, std::string addres, std::string phon, double hourpay, double hrswrked)

你将其称为

Employee emp(num1, steve, 58s200w, 90210, hourwage, hourworked);

你可以直接看到差异，Employee类构造函数期望第2，第3和第4个参数为String。所以你必须将这些参数作为字符串传递。您必须将字符串声明为hourwage，按照您的定义声明小工作变量，或者您必须按照上面解释的名称传递参数。

C ++创建一个类对象

2 个答案: