- An array can be passed to a function by using pointers.
- Whenever the name of the array is passed to the function, the address of the 0th element of the array is copied to the local pointer variable in that function.
- On declaring a formal parameter in the function header as an array, it will be interpreted as a pointer to a variable and not an array.
- With this all the elements of the array can be accessed by using the array_name+index.
Syntax:
func(int arr[]);
OR
func(int *arr);
func (int arr[], int n);
OR
func(int *arr, int n);
Example : Swapping two numbers by using pointers & function
#include <stdio.h>
void swap(int *x,int *y);
void main()
{
int n1=10,n2=20;
swap(&n1,&n2); /* address of n1 and n2 is passed to swap function */
printf("Number1 = %d\n",n1);
printf("Number2 = %d",n2);
}
void swap(int *x,int *y) /* pointer x and y points to address of n1 and n2 respectively */
{
int t;
t = *x;
*x = *y;
*y = t;
}
Output:
Number1 = 20
Number2 = 10
