聲明函數

Question

大家好，請看看我的程序，並幫我找出它有什麼問題。它編譯並運行。該程序要求用戶輸入等級，輸入後將計算總預備等級，並顯示總等級的相應備註。但是，這是我的問題，相應的評論根本不顯示，它只顯示評論的無效輸入。請幫助我謝謝。

#include<iostream> 
#include<conio.h> 

using namespace std; 

void computePG(double& pScore); 
void Remark(double pScore); 

int main() 
{ 
    double cPrelimGrade; 

    cout << "\n\n\tThis program is intended to compute the prelim grade\n"; 

    computePG(cPrelimGrade); 
    Remark(cPrelimGrade); 

getch(); 
} 


    void computePG(double& pScore) 
    { 
    double q1, q2, q3, pe, cpScore = 0; 

    cout << "\n\n\tPlease enter your score in quiz 1: "; 
    cin >> q1; 
    cout << "\tPlease enter your score in quiz 2: "; 
    cin >> q2; 
    cout << "\tPlease enter your score in quiz 3: "; 
    cin >> q3; 
    cout << "\tPlease enter your score in prelim exam: "; 
    cin >> pe; 
    cpScore = ((q1/30) * 20) + ((q2/50) * 20) + ((q3/40) * 20) + ((pe/100) * 40); 
    cout << "\n\n\tThe computed PG is: " << cpScore; 
    } 


    void Remark(double pScore) 
    {  
     if (pScore<=59&&pScore>=0) 
      cout << "\n\tRemark: E"; 
     else if (pScore<=69&&pScore>=60) 
      cout << "\n\tRemark: D"; 
     else if (pScore<=79&&pScore>=70) 
      cout << "\n\tRemark: C"; 
     else if (pScore<=89&&pScore>=80) 
      cout << "\n\tRemark: B"; 
     else if (pScore<=100&&pScore>=90) 
      cout << "\n\tRemark: A"; 
     else 
      cout << "\n\t\tInvalid input"; 
    } 

Answer 1

你傳入pScore作爲參考，但你是不是分配給它的任何值，而不是你存儲你的結果到局部變量cpScore：

void computePG(double& pScore) 
    { 
    double q1, q2, q3, pe, cpScore = 0; 

    cout << "\n\n\tPlease enter your score in quiz 1: "; 
    cin >> q1; 
    cout << "\tPlease enter your score in quiz 2: "; 
    cin >> q2; 
    cout << "\tPlease enter your score in quiz 3: "; 
    cin >> q3; 
    cout << "\tPlease enter your score in prelim exam: "; 
    cin >> pe; 
    pScore = ((q1/30) * 20) + ((q2/50) * 20) + ((q3/40) * 20) + ((pe/100) * 40); 
    cout << "\n\n\tThe computed PG is: " << pScore; 
    } 

Answer 2

變量double& pScore不是由功能更新computePG。