class Tuple{public: int * arr; Tuple(){ int a[10]; arr = a; for (int i = 0; i < 10; ++i) { a[i] = 0; } } void input(int i, int v){ arr[i] = v; } void output(int i){ cout << "arr[" << i << "] = " << arr[i] << endl; }};int main(){ Tuple t; t.input(5,10); t.output(5); return 0;}這個是給arr[i]賦值（input和ouput）
這裏面有一個問題
void output(int i){ cout << "arr[" << i << "] = " << arr[i] << endl; }這一段如果換成void output(int i){ cout << "arr[" << "] = " << arr[i] << endl; }運行結果會顯示被函數改變的值10為什麼？？？？