使函数在C++中正常工作

Question

我发布的代码是来自Nell Dale一书的一个例子。我没有得到预期的功能PrintResults的结果。它显示所有值0.

如何使它工作？在哪里把功能给出确切的结果？我在ubuntu中使用code::Block。该问题计算草坪工作账单并打印到文件中。输入文件格式是。

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

// Function prototypes 
void OpenFiles(ifstream& inFile, ofstream& outFile); 
/* Open file reads in the name of input files & output files and open 
it for processing*/ 
void ProcessClients(ifstream& inFile, ofstream& outFile, float hourlyRate); 
// write bill for all the clients in the infile 
void ProcessAClient(ifstream& inFile, ofstream& outFile, int totalTime, float hourlyRate); 
//For writing the bill of a client 
void GetAndPrintAdress(ifstream& inFile, ofstream& outFile); 
// Reads adress from the file and prints to outfile 
void PrintResults(int numberofBills, int totalMinutes, float hourlyRates); 
// to print total bill average time for job and average bill 

int main() 
{ 
    float hourlyRate; 
    ifstream inFile; 
    ofstream outFile; 
    OpenFiles(inFile, outFile); 
    if(!inFile || !outFile) 
    { 
     cout << "Error opening files"<< endl; 
     return 1; 
    } 
    cout << "Enter Hourly Rate"<< endl; 
    cin >> hourlyRate; 
    ProcessClients(inFile, outFile, hourlyRate); 
    inFile.close(); 
    outFile.close(); 
    return 0; 
} 
//************************************************************************************// 
void OpenFiles(ifstream& inFile, ofstream& outFile) 
{ 
    string inFileName; 
    string outFileName; 
    cout << "Enter the name of infile" <<endl; 
    cin >> inFileName; 
    inFile.open(inFileName.c_str()); 
    cout << "Enter the name of out File"<< endl; 
    cin >> outFileName; 
    outFile.open(outFileName.c_str()); 
    outFile << "Billing for clients on file "<< inFileName <<endl; 
    outFile << fixed; 
} 
//******************************************// 
void ProcessClients(ifstream& inFile, ofstream& outFile, float hourlyRate) 
{ 
    int totalTime=0; 
    int numberofBills=0; 
    string name; 
    getline(inFile, name); 
    while(inFile) 
    { 
     outFile<< name<< endl; 
     ProcessAClient(inFile, outFile, totalTime, hourlyRate); 
     numberofBills++; 
     getline(inFile, name); 
    } 
    PrintResults(numberofBills, totalTime, hourlyRate); 
} 
//*************************************************** 
void PrintResults(int numberofBills, int totalMinutes, float hourlyRate) 
{ 
    cout << "minutes: "<<totalMinutes<<endl; 
    float minutes = static_cast<float>(totalMinutes); 
    cout << "Total amount billed this month is "<< minutes/60.0 * hourlyRate<<endl; 
    cout << "Average time worked per job is "<< minutes/float(numberofBills)/60.0<< endl; 
    cout << "Average customer bill "<< minutes/60.0*hourlyRate/float(numberofBills)<< endl; 
} 
//**************************************************************************** 
void GetAndPrintAdress(ifstream& inFile, ofstream& outFile) 
{ 
    string line; 
    getline(inFile, line); 
    outFile<< line<<endl; 
    getline(inFile, line); 
    outFile<< 

    line<<endl<<endl; 
    } 
    //*********************************************************************************** 
    void ProcessAClient(ifstream& inFile, ofstream& outFile, int totalTime, float hourlyRate) 
    { 
     int time=0; 
     int hours; 
     int minutes; 
     float cost; 
     int numberofJobs; 
     GetAndPrintAdress(inFile, outFile); 
     inFile >> numberofJobs; 
     outFile << "Number of jobs "<< numberofJobs<< endl; 
     for(int count=1; count<=numberofJobs; count++) 
     { 
      inFile >> hours>> minutes; 
      time =hours*60+minutes+time; 
      outFile << "Job "<< count<< ":"<< hours<< " hours and "<< minutes<< " minutes "<< endl; 
     } 
     cost=static_cast<float>(time)/60.0*hourlyRate; 
     totalTime=totalTime+time; 
     outFile << "Amount of Bill "<< setprecision(2)<< cost<<endl<<endl; 
     string skip; 
     getline(inFile, skip); 
    } 

Answer 1

正如在“某程序员家伙”的评论中提到的，问题出在ProcessAClient()。该方法是目前构建的方法如下：

void ProcessAClient(ifstream& inFile, ofstream& outFile, int totalTime, float hourlyRate) 

和方法是通过将其输入文件，输出文件，总时间为所有的客户在输入文件调用，而每小时收费待充电。然后使用总时间计算PrintResults()中输入文件的摘要。

但是，您的问题是变量totalTime的作用域为ProcessAClient()方法。您需要确保通过引用传递值。简单地更新的ProcessAClient()两个定义是：

void ProcessAClient(ifstream& inFile, ofstream& outFile, int& totalTime, float hourlyRate) 

的&前totalTime指出。