ExchangeMoney in C#

// Keeps track of other inventories within collider2D trigger area
// Can exchange money with other inventory by calling TradeMoney when another inventory
// is within the area
public class Inventory {

    public int money = 0;

    void OnTriggerEnter2D(Collider2D collider) {
        // Store reference to inventory within area
        Inventory otherInventory = collider.GetComponent<Inventory>();

        if(otherInventory != null) {
            connectedInventory = otherInventory;
        }
    }

    void OnTriggerExit2D(Collider2D collider) {
        // Remove reference to leaving inventory
        Inventory otherInventory = collider.GetComponent<Inventory>();

        if(otherInventory != null) {
            connectedInventory = null
        }
    }

    public bool TradeMoney(int amount) {
        if(connectedInventory) {
            connectedInventory.money += amount;
            money -= amount;

            // Success
            return true;
        } else {
            // No connected inventory found so can't trade money
            return false;
        }
    }

}