Hi,

As we all know that Swift comes with new and variety of enhancements over objective C. Returning a function as a return type of a function is also one of them.

Here we are defining two functions which are accepting Int kind of parameter and returning Int value.

func increase(_ number: Int ) ->  Int{
     return number + 1
}
        
func decrease(_ number: Int ) ->  Int {
     return number - 1
}

Now we are going to create a new function having function as a return type.       

func myFunction(shouldIncrease: Bool ) -> (Int) -> Int {
      return shouldIncrease ? increase : decrease
}

In this case ‘myFunction’ is accepting a parameter of Bool kind and returning a function(which is accepting a parameter of Int kind and returning Int value).

Above function can be used as:

let modify = myFunction(shouldIncrease: true)

Here ‘modify’ is assigned as a function which is being returned as a value by ‘myFunction’. Now ‘modify’ will operate with one param of Int kind and will return Int value.
example:

let modifiedNumber = modify(20)

That way you can use function as a return type in your program and can make your program more flexible.

Thank you