How to use array pointer
Arrays and pointers
The address of an array is represented by the array name.
#include <stdio.h>
/*from w w w . java 2 s .c o m*/
void main()
{
char multiple[] = "I am a string";
printf("\nThe address of the first array element : %p", &multiple[0]);
printf("\nThe address obtained from the array name: %p\n", multiple);
}
The following code accesses the first element in an array by using both array index and array pointer.
#include <stdio.h>
/*from w w w . ja v a 2 s. c o m*/
void main()
{
char s[] = "a string";
printf("value of second element: %c\n", s[1]);
printf("value of s after adding 1: %c\n", *(s + 1));
}
The name of an array is the same as &array[ 0 ].
#include <stdio.h>
//from w w w.j ava 2 s . com
int main()
{
char array[ 5 ];
printf( " array = %p\n&array[0] = %p\n"
" &array = %p\n",
array, &array[ 0 ], &array );
return 0;
}
The code above generates the following result.
The following code uses the same techniques to get the address of an array.
#include <stdio.h>
/*from w ww. j a v a2s .c om*/
int main(void)
{
char multiple[] = "My string";
char *p = &multiple[0];
printf("\nThe address of the first array element : %p", p);
p = multiple;
printf("\nThe address obtained from the array name: %p\n", p);
return 0;
}
The code above generates the following result.
When the pointer is incremented by an increment operator, it is always right incremented and points to the next value.
#include <stdio.h>
/*from w ww . j a v a2s .c om*/
main(){
int a[5];
int i;
for(i = 0;i<5;i++){
a[i]=i;
}
int *b;
b=a;
for(i = 0;i<5;i++)
{
printf("value in array %d and address is %16lu\n",*b,b);
b++;
}
}
Pointer subscript notation vs Pointer/offset notation
Pointer subscript notation
#include <stdio.h>
// w ww . j a v a2 s. com
int main()
{
int b[] = { 10, 20, 30, 40 };
int *bPtr = b;
int i;
int offset;
for ( i = 0; i < 4; i++ ) {
printf( "bPtr[ %d ] = %d\n", i, bPtr[ i ] );
}
return 0;
}
The code above generates the following result.
Pointer/offset notation
#include <stdio.h>
/*from w ww .j av a 2 s . c om*/
int main()
{
int b[] = { 10, 20, 30, 40 };
int *bPtr = b;
int i;
int offset;
for ( offset = 0; offset < 4; offset++ ) {
printf( "*( bPtr + %d ) = %d\n", offset, *( bPtr + offset ) );
}
return 0;
}
The code above generates the following result.
