Removes the specified number of elements from the beginning of the collection.
mutating func removeFirst(_ k: Int)
The number of elements to remove from the collection.
kmust be greater than or equal to zero and must not exceed the number of elements in the collection.
var bugs = ["Aphid", "Bumblebee", "Cicada", "Damselfly", "Earwig"] bugs.removeFirst(3) print(bugs) // Prints "["Damselfly", "Earwig"]"
Calling this method may invalidate any existing indices for use with this collection.