Question

这是我得到的错误。

CruiseShip.h：10：错误：预期';'在'::'标记之前

CruiseShip.cpp：8：错误：预期'）'在'name'之前制作：***

[CruiseShip.o]错误1

CruiseShip.h

CruiseShip(std::string name,std::string year, int maxPassengers)::Ship(std::string name,std::string year);

CruiseShip.cpp

CruiseShip(string name, string year, int maxPassengers)::Ship(string name, string year){
    maxPassengers=0;
}

这些是发生错误的行。

以下是其余代码：的 CruiseShip.cpp

#include <iostream>
#include "Ship.h"
#include "CruiseShip.h"
using namespace std;



CruiseShip(string name, string year, int maxPassengers)::Ship(string name, string year){
    maxPassengers=0;
}

void CruiseShip::setPass(int maxPassengers){
    this->maxPassengers=maxPassengers;
}
int CruiseShip::getPass(){
    return maxPassengers;
}

void CruiseShip::print(){
    cout<<"The name of the ship is "<<getName()<<endl;
    cout<<"The capacity of the ship is "<<maxPassengers<<endl;

}

CruiseShip.h

#ifndef CRUISESHIP_H_
#define CRUISESHIP_H_
#include <string>
class CruiseShip: public Ship{
protected:
    int maxPassengers;


public:
    CruiseShip(std::string name,std::string year, int maxPassengers)::Ship(std::string name,std::string year);
    void setPass(int);
    int getPass();
    virtual void print();

};
#endif

Answer 1

显然，CruiseShip继承自Ship。

声明应该只说明构造函数的原型，

CruiseShip(std::string name, std::string year, int maxPassengers);

并且定义进行了初始化：

CruiseShip::CruiseShip(string name, string year, int maxPassengers) 
   : Ship(name, year),
     maxPassengers(maxPassengers) 
{

}

请注意，只有一个冒号，并且基类初始化没有提及类型，就像函数调用一样。
此外，构造函数定义需要范围规范CruiseShip::。

Answer 2

这条线似乎没有任何意义。
您认为它应该做什么？

CruiseShip(std::string name,std::string year, int maxPassengers)::Ship(std::string name,std::string year);

它看起来像class CruiseShip的构造函数的开头，但在开始看起来像::的构造函数之前有一个作用域（class Ship）。

以下是我的意思：

在标题（.h）文件中：

#pragma once
#include <string>
using std::string;
class CruiseShip :
    public Ship   // Class inherits from base-class Ship
{
    // Constructor takes 3 parameters:
    CruiseShip(const string& name, const string& year, int maxPassengers);
};

在实施（.cpp）文件中：

// Implementation of the Constructor, which begins by passing
// name and year to the Base-Class constructor.
// Then completes the constructor by handling the maxPassengers parameter.
CruiseShip::CruiseShip(const string& name, const string& year, int maxPassengers): 
    Ship(name, year)  // Call the base-class constructor
{
    this->maxPassengers = maxPassengers; // Also assign member variable.
}

<小时/> 其他几点说明：

如果没有充分的理由传递值，通常应该通过const-reference传递变量。这将避免不必要的复制构造函数。
使用#ifdef - #endif来避免整个#pragma once保护，现在大多数主要编译器都支持using namespace std;。
不要using std::string;。它带来了整个命名空间，这非常大。只需导入您需要的内容：outFile.open("Final output.txt"); // print the report title and column headings outFile << " Meet Report" << endl; outFile << "Gender Weight Class(LBS) Squat Bench Deadlift Wilks" << endl; outFile << "---------------------------------------------------------------------" << endl; // serves as the first input for sentinel loop and determining the correct formula for wilks calculation cout << "Please enter your gender (male/female, or e to end): "; cin >> gender; cout << endl; while (gender != "male" && gender != "female") { cout << "Incorrect input. Please try again." << endl; cout << "Please enter your gender (male/female, or e to end): "; cin >> gender; cout << endl; } while (gender == "male") { cout << "Please use kilograms (KG) for all inputs." << endl; cout << "Enter your bodyweight: "; cin >> weight; cout << "Enter your final bench press attempt: "; cin >> bench; cout << "Enter your final squat attempt: "; cin >> squat; cout << "Enter your final deadlift attempt: "; cin >> deadlift; total = bench + squat + deadlift; wilksCalc = 500 / (A_MEN + B_MEN * (weight) + C_MEN * (weight * weight) + D_MEN * (weight * weight * weight) + E_MEN * (weight * weight * weight * weight) + F_MEN * (weight * weight * weight * weight * weight)); wilks = wilksCalc * total; cout << wilks; cout << endl; outFile << left << setw(21) << gender; outFile << weight; outFile << right << setw(11) << squat; outFile << right << setw(11) << bench; outFile << right << setw(11) << deadlift; outFile << right << setw(11) << wilks; if (gender == "female") { cout << "Please use kilograms (KG) for all inputs." << endl; cout << "Enter your bodyweight: "; cin >> weight; cout << "Enter your final bench press attempt: "; cin >> bench; cout << "Enter your final squat attempt: "; cin >> squat; cout << "Enter your final deadlift attempt: "; cin >> deadlift; total = bench + squat + deadlift; wilksCalc = 500 / (A_WOMEN + B_WOMEN * (weight) + C_WOMEN * (weight * weight) + D_WOMEN * (weight * weight * weight) + E_WOMEN * (weight * weight * weight * weight) + F_WOMEN * (weight * weight * weight * weight * weight)); wilks = wilksCalc * total; cout << wilks; cout << endl; outFile << left << setw(21) << gender; outFile << weight; outFile << right << setw(11) << squat; outFile << right << setw(11) << bench; outFile << right << setw(11) << deadlift; outFile << right << setw(11) << wilks; } } outFile.close(); return 0; }（请参阅This Topic）

Answer 3

您的Ship类必须包含以下内容：

Ship(std::string,std::string);

在公开声明中。因为这是您在CruiseShip

中提供参数时要调用的内容

以这种方式构建具有内在性的正确构造函数的方式是：

CruiseShip::CruiseShip(string name, string year, int maxPassengers):Ship(name,year){
    maxPassengers=0;
}

您正在使用参数Ship(std::string,std::string)调用构造函数，该参数使用CruiseShip给出的参数。您只需告诉程序您要提供哪些变量

你的CruiseShip课程因为它错了。您没有告诉程序先调用Ship

#ifndef CRUISESHIP_H_
#define CRUISESHIP_H_
#include <string>
class CruiseShip: public Ship{
protected:
    int maxPassengers;


public:
    CruiseShip(std::string name,std::string year, int maxPassengers);
    void setPass(int);
    int getPass();
    virtual void print();

};
#endif

C ++中的编译器错误

3 个答案: