Chapter 10, Problem 24RQE

Program Plan Intro

Pointer:

Pointer, the name itself references the purpose of the pointer. Pointers point to a location in memory.

• Pointer is a special type of variable to store the address of the memory location, which can be accessed later.
• If an asterisk “*” operator is present before the variable, then that variable is referred as pointer variable.
  • It is also called as dereferencing or indirection operator.
• Pointer is just a type of variable that stores the addresses of other variables.
• Using pointers, we can access the address of a variable; the data stored in that variable can be retrieved.

Syntax of pointer variable declaration:

<variable-type> *<variable-name>;

Constant pointer:

 Value that a constant pointer holds can be changed, whereas the address of the pointer variable holds cannot be changed is called as a “constant pointer”.

• Constant pointer is where the address hold by the pointer variables remains constant, whereas the value can change during the execution.
• Address of the pointer remains constant throughout the execution.

Syntax of constant pointer:

<variable-type> * const <variable-name>;

Example:

Consider the below constant pointer definition:

double a = 12.32;

double * const pointer = &a;

• In above statement, the variable “a” is defined with double value and it is pointed by a constant pointer “pointer”, which points to const double.