public class createStockItems {

        public static void createSampleStockItems(Integer numberOfItems) {
		//Putting new stock items into a  list to bulkify the code
		List<Stock_Item__c> stockItemsList = new List<Stock_Item__c>();
        //Loop through and add stock items:
		for (Integer i = 0; i < numberOfItems; i++) {
			System.debug('i = ' + i);
            Stock_Item__c si = new Stock_Item__c();
            si.Item_Name__c = 'Sample Stock Item ' + (i+1);
            si.Description__c = 'Lorem ipsum dolor sit amet ' + (i+1);
            si.List_Price__c = (i+1)+(i+1);
            si.Minimum_Stock_Level__c = 3;
            si.Stock_on_Hand__c = (i+1)+(i+1);
			stockItemsList.add(si);
		}
        //Inserting all in one action:
		insert stockItemsList;
        System.debug('Inserted ' + stockItemsList.size() + ' stock items.');

    }
}