Where in the Motoko documentation is this question mark before a type described? for example
type Bits = {next : () → ?Bool};
What does “?” in that position do?
Where in the Motoko documentation is this question mark before a type described? for example
type Bits = {next : () → ?Bool};
What does “?” in that position do?
The ?
is used to specify optional types: Language quick reference | Internet Computer Home.
It means the value can either be a null
type or the type defined after it.
In this case, it’s either a null or a Boolean value.