Allocating a Fixed - Dimensional Array
The new operator, when used with the name of a pointer to a datatype allocates memory for the item and assigns the address of that memory to the pointer.
This example shows how you can use new and delete to acquire and dispose of memory for an array.
# include <iostream.h>
int main ( )
{
int *q = new int [ 3 ] ;
q [ 0 ] = 6 ;
q [ 1 ] = 7 ;
q [ 2 ] = 8 ;
cout << q [ 0 ] << q [ 1 ] << q [ 2 ] ;
delete [ ] q ;
return 0 ;
}
Allocating Dynamic Arrays
You can supply a variable dimension, and the new operator allocates the correct amount of memory.
This example shows how you can use new and delete to acquire and dispose of memory for a variable dimension array.
# include <iostream.h>
int main ( )
{
cout << " Enter the array size " ;
int size ;
cin >> size ;
int *q = new int [ size ] ;
for ( int i = 0 ; i < size ; i++ ) // load the array with 1, 2 ..... size
q [ i ] = i + 1 ;
for ( int i = 0 ; i < size ; i++ ) // displays elements in the array
cout << q [ i ] ;
delete [ ] q ;
return 0 ;
}
When running this exercise, you first type in the size of the array. The new operator uses that value to establish the size of the memory to be allocated. The program builds the array by using the new operator, fills it with values ( 1, 2 ....... size ), displays each of the elements in the array, and deletes the array by using the delete operator.