Pointer
data type used to access memory and manipulate address.
pointer variable contains the physical memory address of variable (“*” point to it) e.g.. the declaration int i,*p; declare i of type int, and p to be of type pointer. In this case p will take address of a int as values. (e.g.. p=&i; p=0; p=NULL; p=(int *) 1307;)
Addressing and dereferencing: & address-of operator
while (scanf(“%lf”, &ThisItem ) == 1 )