Pointer Variables in C Language

In C programming language, a pointer variable is a variable that stores the memory address of another variable. This allows the programmer to indirectly access and manipulate the value of the other variable by using the pointer.

A pointer variable is declared using the asterisk (*) symbol before the variable name. For example, the following code declares a pointer variable called “ptr” that can hold the memory address of an integer:

int *ptr;

To assign a value to the pointer, we can use the address-of operator (&) to get the memory address of an integer variable, and then assign that address to the pointer. For example:

int num = 10;
ptr = #  // ptr now points to the memory address of num

To access the value of the variable that the pointer points to, we can use the dereference operator (*) to obtain the value stored in the memory address. For example:

printf("The value of num is %d\n", *ptr);  // prints "The value of num is 10"

Pointer variables are commonly used in C for various purposes, including dynamic memory allocation, passing arguments to functions by reference, and implementing data structures such as linked lists and trees.