In Swift, a set is used to store unique elements of the same data type.
Creating a Set
To create a set populated with values, use the
Set keyword before the assignment operator.
The values of the set must be contained within brackets
 and separated with commas
An empty set is a set that contains no values inside.
Iterating Over a Set
in loop can be used to iterate over each item in a set.
Use the built-in property
.isEmpty to check if a set has no values contained in it.
.count returns the number of elements contained within a set.
||Add an element at a specified index|
||Remove an element at a specified index|
||Remove every single value from a set|
||Check whether an item exists within the set|
||Populates a new set of elements with the overlapping elements of two sets|
||Populates a new set by taking all the values from two sets and combining them|
||Creates a new set with all the non-overlapping values between two sets|
||Removes the values of one second set from another set and stores the remaining values in a new set|