循环不工作

当我运行程序时，它结束了平均值，但它不会循环！有谁看到我做错了，我指出了正确的方向循环不工作

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

//function prototypes 

void getTestScores(double &score1, double &score2, double &score3); 
double calcAverage(double &score1, double &score2, double &score3); 
void displayAverage(double avg); 

int main() 
{ 
    //declare variables 
    double score1 = 0.0; 
    double score2 =0.0;  
    double score3 = 0.0; 
    double avg = 0.0; 

    //display average in fixed-point notation 
    getTestScores(score1,score2,score3);  
    calcAverage(avg); 
    displayAverage(avg); 

    //enter scores 
    while (avg != -1); 
    { 
     cout << "score 1 (negative number to stop): "; 
     cin >> score1; 
     cout << "Enter score 2(negative number to stop): "; 
     cin >> score2; 
     cout << "Enter score 3(negative number to stop): "; 
     cin >> score3; 

     calcAverage(score1, score2, score3); 
     displayAverage(avg); 

     return 0; 
    } 
} //end of main function 

//*****function prototypes***** 
void getTestScores(double &score1, double &score2, double &score3) 
{ 
    cout << "Enter score 1(negative numberto stop): "; 
    cin >> score1; 
    cout << "Enter score 2(negative number to stop): "; 
    cin >> score2; 
    cout << "Enter score 3(negative number to stop): "; 
    cin >> score3; 
} //end 

double calcAverage (double &score1, double &score2, double &score3) 
{ 
    double average = 0.0; 
    average = calcAverage(score1, score2, score3); 

    return average; 
} //end of clacAverage 

void displayAverage(double avg)  
{ 
    cout << fixed << setprecision(1); 
    cout << "Average: " << avg << endl; 
} //end

来源

2011-04-21 Katie

使用4位代码的每个语句之前，或只选择整个代码，点击'{}'本编辑器选项卡上。 – Mahesh 2011-04-21 06:48:42

为什么你需要'calcAverage'中的三个参数，就像这个'double calcAverage（double＆score1，double＆score2，double＆score3）;'但是给出这样一个参数'calcAverage（avg）;'？我不是一个C++的男孩我很抱歉，如果我问的是noob.Also我认为你应该在（平均！= -1）' – Bastardo 2011-04-21 06:52:57

（平均！= -1）之后移除';'：不要直接比较浮点数（请参阅http://how-to.wikia.com/wiki/Howto_compare_floating_point_numbers_in_the_C_programming_language） – stefaanv 2011-04-21 07:08:44