指標(五)————傳遞指標給函式
阿新 • • 發佈:2018-11-14
#include <iostream> using namespace std; void getSeconds(int *par); double getAverage(int *arr, int size);//入參是指標,本質上是要求傳一個地址過來 int main () { int sec=5; cout << "sec :" << sec << endl; getSeconds( &sec ); //傳遞地址 cout << "sec is changed by the pointer :" << sec << endl; // 輸出實際值 // 帶有 5 個元素的整型陣列 int balance[5] = {1000, 2, 3, 17, 50}; double avg; // 傳遞一個指向陣列的指標作為引數 avg = getAverage( balance, 5 ) ;//balance是陣列,本質上是一個指向陣列首元素的地址 // 輸出返回值 cout << "Average value is: " << avg << endl; return 0; } void getSeconds(int *par) { *par = 100; return; } double getAverage(int *arr, int size) { int i, sum = 0; double avg; for (i = 0; i < size; ++i) { sum += arr[i]; } avg = double(sum) / size; return avg; }
結果
sec :5
sec is changed by the pointer :100
Average value is: 214.4
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