Chapter 7: Empty Function

In the previous chapter, we defined the logic of a pokemon battle and returned the wild pokemon details if the trainer pokemon wins.

But what if the trainer pokemon loses? In such a case we need to return some empty values.

empty(typename) → Any

empty is a built-in Vyper function which returns a default value of the type(typename) passed as a parameter.

It is useful for initializing new memory variables.

@external
def someFunction():
   name: String[32] = empty(String[32])

Here you can find a list of all types and default values:

We will use the empty function to return default values in case the trainer pokemon loses.

Create an else statement which returns the following values:
- Battle result: False
- Wild pokemon name: empty(String[32])
- Wild pokemon DNA: empty(uint256)
- Wild pokemon HP: empty(uint256)