Null pointer exception on 'store.storeProducts[i]' line

//interface
//related variables
Store store = new Store();

public void run()
{
    for (int i = 0; i < store.maxNumberOfProducts; i++)
    {
        store.storeProducts[i] = new Product();
    }

}

//end interface

//store
//related variables
int maxNumberOfProducts = 3;
Product[] storeProducts;

//constructors
// set and get methods