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iOS Swift Protocols Protocols Protocols as Types

Posted by Roberta Voulon
Roberta Voulon
5,792 Points

When do we need to add parentheses() after a protocol name?

In this video Pasan has us write the following line:

var d6 = Dice(sides: 6, generator: LinearCongruentialGenerator())

I'm wondering why we need to write the parentheses() after the protocol LinearCongruentialGenerator, especially as we haven't had to do so in the previous examples, like the one for Blendable:

let ingredients: [Blendable] = [strawberry, chocolateMilk]

1 Answer

Roberta Voulon
Roberta Voulon
5,792 Points

Ah cripes, I just figured out that the protocol actuall is RandomNumberGenerator and the class LinearCongruentialGenerator implements it... my bad :)

Stepan Ulyanin
Stepan Ulyanin
11,318 Points

LinearCongruentialGenerator is a class and you need to create an instance of the class, so you use: LinearCongruentialGenerator() (only if you won't specify any other initializers), the class conforms to protocol, it is not a protocol itself