How to do it...

Let's look at some example code that allocates a pointer variable, i, then assigns memory to it using malloc(). We allocate a single integer behind an int* pointer. After allocation, we store a value inside int, using the dereferencing operator *:

// CREATING AND ALLOCATING MEMORY FOR AN INT VARIABLE i 

// Declare a pointer variable i 
int * i; 

// Allocates system memory
i = ( int* )malloc( sizeof( int ) );

// Assign the value 0 into variable i 
*i = 0; 

// Use the variable i, ensuring to 
// use dereferencing operator * during use 
printf( "i contains %d", *i ); 

// RELEASING MEMORY OCCUPIED BY i TO THE SYSTEM 

// When we're done using i, we free the memory 
// allocated for it back to the system. 
free( i ); 

// Set the pointer's reference to address 0 
i = 0;