數組指針動態C++

Question

#include <iostream> 
using namespace std; 

void main() 
{ 

    int numDays; 
    double sum = 0; 
    double avg; 
    cout << "Enter the number of days of sales"; 
    cin >> numDays; 
    double *Sales = new double[numDays]; 

    for (int i = 0; i < numDays; i++) 
    { 
     cout << "enter how much you sold for day " << i << endl; 
     cin>>*Sales; 

     sum = sum + *Sales; 

     cout << Sales; 
    } 

    delete[] Sales; 
    avg = sum/(numDays); 
    cout << "the sum is" << sum << endl; 
    cout << "the avg is" << avg << endl; 
} 

嗨，這是我得到的輸出可以somone解釋爲什麼指針不需要增加？以及用指針完成相同任務的正確方法。

Enter the number of days of sales2 
enter how much you sold for day 0 
1 
0050CD70enter how much you sold for day 1 
2 
0050CD70the sum is3 
the avg is1.5 
Press any key to continue . . . 

Answer 1

這樣做有幾種樣式。您可以索引到陣列本身：

double *Sales = new double[numDays]; 
for (int i = 0; i < numDays; i++) 
{ 
    cout << "enter how much you sold for day " << i << endl; 
    cin >> Sales[i]; 
    sum = sum + Sales[i]; 
} 

或者您可以前進一個指針，確保保留原始指針的副本。在下一個示例中，p的目標沿着Sales的指數蠕變。 （請確保不使用上pdelete，因爲它不是用new創建！）

double *Sales = new double[numDays]; 
double *p = Sales; 
for (i = 0; i < numDays; i++) 
{ 
    cout << "enter how much you sold for day " << i << endl; 
    cin >> *(p++); 
} 

（從技術上講不需要在*(p++)括號，而實際上有很多的代碼，使用而不是），而不是）。