Program to merge two 1-D arrays

Here is the program in cpp:

#include <iostream.h>
#include <conio.h>

using namespace std;
const int MAX1 = 5 ;
const int MAX2 = 7 ;

class array
{
    private :

        int *arr ;
        int size ;

    public :

        void create ( int sz ) ;
        void sort( ) ;
        void display( ) ;
        void merge ( array &a , array &b ) ;
} ;

// creates array of given size sz, dynamically
void array :: create ( int sz )
{
    size = sz ;
    arr = new int[size] ;

    int n ;

    for ( int i = 0 ; i < size ; i++ )
    {
        cout << "\nEnter the element no. " << ( i + 1 ) << " " ;
        cin >> n ;
        arr[i] = n ;
    }
}

// sorts array in ascending order
void array :: sort( )
{
    int temp ;
    for ( int i = 0 ; i < size ; i++ )
    {
        for ( int j = i + 1 ; j < size ; j++ )
        {
            if ( arr[i] > arr[j] )
            {
                temp = arr[i] ;
                arr[i] = arr[j] ;
                arr[j] = temp ;
            }
        }
    }
}

// displays the contents of array
void array :: display( )
{
    for ( int i = 0 ; i < size ; i++)
        cout << "  " << arr[i] ;
}

// merges two arrays of different size
void array :: merge ( array &a, array &b )
{
    int i, k, j ;
    size = a.size + b.size ;

    arr = new int[size] ;

    for ( k = 0, j = 0, i = 0 ; i <= size ; i++ )
    {
        if ( a.arr[k] < b.arr[j] )
        {
            arr[i] = a.arr[k] ;
            k++ ;
            if ( k >= a.size )
            {
                for ( i++ ; j < b.size ; j++, i++ )
                    arr[i] = b.arr[j] ;
            }
        }
        else
        {
            arr[i] = b.arr[j] ;
            j++ ;
            if ( j >= b.size )
            {
                for ( i++ ; k < a.size ; k++, i++ )
                    arr[i] = a.arr[k] ;
            }
        }
    }
}

int main( )
{
    array a ;
    cout << "\nEnter elements for first array: \n" ;
    a.create ( MAX1 ) ;

    array b ;
    cout << "\nEnter elements for second array: \n" ;
    b.create ( MAX2 ) ;

    a.sort( ) ;
    b.sort( ) ;

    cout << "\nFirst array: \n" ;
    a.display( ) ;
    cout << "\n\nSecond array: \n" ;
    b.display( ) ;
    cout << "\n\nAfter Merging: \n" ;

    array c ;
    c.merge ( a, b ) ;
    c.display( ) ;
}

Still to improve.