这是我第一次使用C ++中的类和头文件，我把代码放在一起后遇到了这些错误
该程序旨在读取和写入文件，同时还可以进行搜索并能够操作二进制文件。我很确定错误出现在我的声明中，但我自己无法弄明白;任何帮助表示赞赏。
的main.cpp
#include <iostream>
#include<iomanip>
#include <fstream>
#include"animals.h"
using namespace std;
int main()
{
Animals nA;
fstream animalFile;
int choice;
cout << setprecision(2) << fixed;
do
{
// Display the menu.
cout << "\n1. Add a new animal\n";
cout << "2. Remove an animal\n";
cout << "3. Search and display a animal\n";
cout << "4. Display all animals\n";
cout << "5. Exit\n";
do
{
cout << "Enter your choice (1-5): ";
cin >> choice;
} while (choice < 1 || choice > 5);
// Process the selection.
switch (choice)
{
// Choice 1 is to add an animal
case 1:
nA.addAnimal(animalFile);
break;
// Choice 2 is to remove an animal
case 2:
nA.removeAnimal(animalFile);
break;
// Choice 3 is to search and display 1 animal
case 3:
nA.searchAnimal(animalFile);
break;
// Choice 4 is to display all animals
case 4:
nA.displayAnimal(animalFile);
}
} while (choice != 5);
system("pause");
return 0;
}
Animals.h
#ifndef ANIMALS_H
#define ANIMALS_H
#include <string>
#include <iostream>
#include <fstream>
class Animals
{
private :
std::string name;
int age;
public :
//Default constructor
Animals();
//Create an animal object
Animals(std::string name, int age);
//Add a new animal record
void addAnimal(fstream &d);
//Remove an animal record
void removeAnimal(fstream &d);
//Displays an animal through a search
void searchAnimal(fstream &d);
//Display ALL animals
void displayAnimal(fstream &d);
};
#endif
Animals.cpp
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include "Animals.h"
using namespace std;
Animals::Animals()
{
name = "NULL";
age = 0;
}
Animals::Animals(std::string name, int age)
{
Animals *newAnimal = new Animals;
}
void Animals::addAnimal(fstream &d)
{
string userName;
int userAge = 0;
int stringRemainder;
int record;
const int RECORD_SIZE = 40;
//Collecting user input
do
{
std::cout << "Please enter your animal name: ";
std::cin >> userName;
std::cout << "\n";
} while (sizeof(userName) > 30);
do
{
std::cout << "Please enter your animal age: ";
std::cin >> userAge;
std::cout << "\n";
} while (userAge <= 0 || !isdigit(userAge));
//Fixing length of string
stringRemainder = 30 - sizeof(userName);
//Finds record number based on position
record = (d.tellg() % RECORD_SIZE) + 1;
//Writing to file
d.close();
d.open("animals.txt", std::ios_base::app | ios::binary);
d << record << "";
d << userName;
for (int i = 0; i < stringRemainder; i++)
{
d << "";
}
d << userAge << "\n";
d.close();
}
void Animals::removeAnimal(fstream &d)
{
int recordNumber = 0;
const int RECORD_SIZE = 40;
char recordBuffer[RECORD_SIZE];
d.open("animals.txt", ios::out| ios::in |ios::binary);
//Collecting user input
do
{
cout << "Enter the record of the animal to be removed: ";
cin >> recordNumber;
} while (recordNumber <= 0 || !isdigit(recordNumber));
// move pointer to desired position, and overwrite!
d.seekp((recordNumber-1) * RECORD_SIZE);
d.write(recordBuffer, RECORD_SIZE);
d.close();
}
void Animals::searchAnimal(fstream &d)
{
int userRecord = 0;
char displayRecord[2];
const int RECORD_SIZE = 40;
char fileOutput[RECORD_SIZE];
string displayInfo;
char displayName[RECORD_SIZE];
char displayAge[2];
int i,k;
int j = 0;
d.open("animals.txt", ios::out | ios::binary);
//Getting user input
do
{
cout << "Enter the record of the animal to be diplayed: ";
cin >> userRecord;
} while (userRecord <= 0 || !isdigit(userRecord));
//Moving pointer position to searched value
d.seekp((userRecord - 1) * RECORD_SIZE);
//Gets data from file, stores into displayInfo
getline(d, displayInfo);
d.close();
//Entering file data into diplay variables,
//value 'i' increments through entire displayInfo array
for (i = 0; isdigit(displayInfo[i]); i++)
{
displayRecord[i] = displayInfo[i];
}
//New sentinel for ONLY string cap including buffer
k = i + 30;
for (i; i < k; i++)
{
displayName[j] = displayInfo[i];
j++;
}
//Finishes off last of the displayInfo array
for (i; i < sizeof(displayInfo); i++) {
displayAge[i] = displayInfo[i];
}
//Prints the data for user
cout << "For record number: " << userRecord << "\n";
cout << "Animal: ";
for (int i = 0; i < strlen(displayName); i++)
{
cout << displayName[i];
}
cout << "\n";
cout << "Age: ";
for (int i = 0; i < strlen(displayAge); i++)
{
cout << displayAge[i];
}
cout << "\n";
}
//Mostly copied from above function, displays ALL animals
void Animals::displayAnimal(fstream &d)
{
int userRecord = 0;
char displayRecord[2];
const int RECORD_SIZE = 40;
char fileOutput[RECORD_SIZE];
string displayInfo;
char displayName[RECORD_SIZE];
char displayAge[2];
int numberOfRecords;
int i, k;
int j = 0;
int q = 0;
d.open("animals.txt", ios::out | ios::in | ios::binary);
d.seekg(0, d.end);
numberOfRecords = d.tellg() % RECORD_SIZE;
d.seekg(0, d.beg);
for (int q; q < numberOfRecords; q++) {
d.seekp(q * RECORD_SIZE);
//Gets data from file, stores into displayInfo
getline(d, displayInfo);
//Entering file data into diplay variables,
//value 'i' increments through entire displayInfo array
for (i = 0; isdigit(displayInfo[i]); i++)
{
displayRecord[i] = displayInfo[i];
}
//New sentinel for ONLY string cap including buffer
k = i + 30;
for (i; i < k; i++)
{
displayName[j] = displayInfo[i];
j++;
}
//Finishes off last of the displayInfo array
for (i; i < sizeof(displayInfo); i++) {
displayAge[i] = displayInfo[i];
}
//Prints the data for user
cout << "For record number: " << userRecord << "\n";
cout << "Animal: ";
for (int i = 0; i < strlen(displayName); i++)
{
cout << displayName[i];
}
cout << "\n";
cout << "Age: ";
for (int i = 0; i < strlen(displayAge); i++)
{
cout << displayAge[i];
}
cout << "\n\n";
}
d.close();
}
答案 0 :(得分：1)
标头<iostream>和<fstream>将其符号带入std命名空间，因此标头中对这些符号的任何引用都需要完全限定;例如std::fstream。此外，您可能希望在标头中包含<iosfwd> - 这可以最大限度地减少导入标头的编译器时间成本，假设标头仅使用对iostream标头中提到的符号的引用。
答案 1 :(得分：1)
您应该将ifstream用于读取文件，将ofstream用于写入文件。
在头文件中，您应该在4个函数的参数中使用std::ifstream & d或std::ofstream & d。