Great job completing this lesson!

Let’s go over what we learned:

• A set is an unordered collection of unique elements.

• We have the option to initialize sets that are either empty or populated:

  var emptySet = Set<Type>()
  var populatedSet: Set = [Value1, Value2, Value3]

• To add new elements to a set, use the built-in method, .insert(Value).

• We can remove a single element from a set using .remove(Value) or we can remove all the values from a set with .removeAll():

• If we want to check if a value exists within a set, we can use the method .contains(Value) .

• A for-in loop can be used to iterate through all the values of a set:

  for placeholder in setName {
  // Body of loop
  }

• We can use set operations to modify or create new sets based on the data in two different sets.

• The .intersection() operation creates sets with values that overlap in two sets:

  soda.intersection(seltzer)

• The .union() operation combines all the values of two different sets:

  ketchup.union(mayo)

• The operation .symmetricDifference() creates a set of items that appear in one set, but not both:

  capulets.symmetricDifference(montagues)

• .subtracting() is a set operation that removes the overlapping data of one set from another:

  milkshake.subtracting(iceCream)