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Never Keyword in Swift

The Never keyword is a special return type in Swift. When this function call occurs, it tells the compiler that exec will never return

According to Apple:-

“The return type of functions that do not return normally, that is, a type with no values.”

Never keyword used by fatalError() and preconditionFailure() functions.

We can use it as a return type when declaring a method, closure, or function that unconditionally throws an error, traps, or otherwise does not terminate.

func method1() -> Never {

    fatalError("Something very, very bad happened")

}

The first note (with regard to secondary error treatment) is perhaps particularly important. A function can never have complex arguments and throws – not necessarily crashes.

Let’s look at some interesting use cases and compare between never and void

Comparision between NEVER and VOID return type :

VOID:

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