Type casting in Swift is implemented with the is and as operators. is is used to check the type of a value whereas as is used to cast a value to a different type.
Read moreWhat is _ mean in Swift?
The _ is not necessary for function calls. It is just used to indicate that something does not need to have a name . In regards to how you would refer to your function, You would not have to pass any name for the function call.
Read moreHow do I use the SF symbol?
How to use SF Symbols in Swift
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