# Breaking changes in beta-3

###### tags: `Internal`

## Sway Changes

### StorageMap `.get()` method returns `Option<>` type

Previously StorageMaps would return a 0 value of the correct type if no value was set for a given key. Now, this method returns an Option type, which can be either `Some(value)` or `None`.

Solution:

Use the `unwrap_or()` method to unwrap the value or return a default value if `None` is found.

### Must use `#[payable]` for payable functions

If you expect to receive assets in a function call, you must use the `payable` annotation. You can add it to a storage annotation like this: `#[storage(read, write), payable]`.

## Examples

### Web3rsvp contract

1. `.get()` returns `Option<>` type

Hence, the following code fails:

storage {
    events: StorageMap<u64, Event> = StorageMap {},
    event_id_counter: u64 = 0,
}

let mut selectedEvent = storage.events.get(storage.event_id_counter - 1);
        return selectedEvent;

**Error:**

return selectedEvent;
       ^^^^^^^^^^^^^^ Mismatched types.
expected: Event
found:    Option<Event>.

### Marketplace contract

1. `.get()` returns `Option<>` type (same as above)

Hence, the following code fails:

require(item.id > 0, InvalidError::IncorrectItemID);

Error:

require(item.id > 0, InvalidError::IncorrectItemID);
        ^^^^^^^ This is a Option<Item>, not a struct. Fields can only be accessed on structs.

Solution:

Use `unwrap_or()`

fn get_item(item_id: u64) -> Item {
    // returns the item for the given item_id
    let selected_item: Option<Item> = storage.item_map.get(item_id);
    selected_item.unwrap_or(
        Item {
            id: u64,
            price: u64,
            owner: Identity,
            metadata: str[20],
            total_bought: u64,
        }
    )