傳送陣列位址到函式

1. 範例二：傳送陣列位址至函式，函式運算會改變陣列內容。

   [dywang@deyu zzz]$ vim pointer9.c
   [dywang@deyu zzz]$ cat pointer9.c
   #include <stdio.h>
    
   float getAverage(int *arr, int size)
   {
   	int i, sum=0;       
   	float avg;          
    
   	for ( i=0; i<size; ++i) {
   		sum += arr[i];
   	}
   	avg = (float)sum/size;
   	return avg;
   }
   
   main () {
   	int balance[] = {1000, 2, 3, 17, 50};
   	float avg;
    
   	avg = getAverage( balance, 5 ) ;
   	printf("Average(1000, 2, 3, 17, 50) = %f\n", avg );
   }
   

2. 編譯

   [dywang@deyu zzz]$ gcc -o pointer9 pointer9.c
   

3. 執行結果

   [dywang@deyu zzz]$ ./pointer9
   Average(1000, 2, 3, 17, 50) = 214.399994