Relationship between 1-Dimensional array and pointer in C programming

                  Array name by itself is an address or pointer. It points to the address of the first element (0th element of an array). Thus, if x is a one dimensional array, then address of the first array element can be expressed as either &x[0] or simple as x. The address of the second array element can be written as either &x[1] or as x+1 and so on. In general, the address of the array element i+1 can be expressed as either &x[i] or as x+i. In the expression x+i, x represents array name (address of first element) whose elements may be integers, characters, float etc and i represents integer quantity. Thus, here x+i specifies an address that is a certain number of memory cells beyond the address of the first array element. Again, x[i] and *(x+i) both represent the content of that address.

     Example:

 To display array element with their address using array name as a pointer.

void main()

{

      int x[5]={2,4,6,8,10}, k;

      printf(“\n element no.      element        address”);

      for(k=0;k<5;k++)

         printf(“\n x[%d]=\t%d %u”,k,*(x+k), x+k);

     

      getch();

      }

  output

Element no.          Element                address

X[0]                                   2                      4056

X[1]                                   4                      4058

X[2]                                   6                      4060

X[3]                                   8                      4062

X[4]                                   10                    4064

         

              In the above program element k acts as the element number and its value varies from 0 to 4. When it is added with an array name ‘x’ i.e. with address of the first element, it points to the consecutive memory location. Thus, element number, element and their addresses are displayed.

 Another example:

           Write a program to calculate average percentage of 10 students in a class using pointer. Read percentage of individual student from user.

Solution:

void main()

  {

  int per[10],i,sum=0;

  clrscr();

  printf("Enter percentage of each student\n");

  for(i=0;i<10;i++)

   {

     scanf("%d",per+i);

     sum+=*(per+i);

   }

  printf("\nThe average is=%d",sum/10);

   getch();

  }