Skip to Content
Learn
Sets
Set Operations: .union()

Another set operation we can use is .union(). This operation creates a set by combining the values of two sets together.

The syntax for creating a set using .union() is:

var NewSet = SetA.union(SetB)

.union()

Consider the following sets book1 and book2 that contain the characters of different fairy tales:

var book1: Set = ["Pig 1", "Pig 2", "Pig 3", "Wolf"] var book2: Set = ["Little Red Riding Hood", "Grandma", "Wolf"]

We can use .union() to combine all the characters into one set called fairyTales:

var fairyTales = book1.union(book2)

Imagine finding a third book, book3:

var book3: Set = ["Jack", "Blunderbore", "Beanstock"]

With set operations, we can combine multiple sets like this:

var fairyTales = book1.union(book2).union(book3)

Using multiple methods in the same line of code is known as method chaining.

When we print fairyTales, we will get something similar to the following output:

["Blunderbore", "Pig 1", "Pig 2", "Little Red Riding Hood", "Pig 3", "Grandma", "Wolf", "Jack", "Beanstock"]

The element "Wolf" appeared in both book1 and book2; however, the element only appears once in fairyTales because sets only contain unique elements.

Instructions

1.

In Alphabet.swift, create a set called alphabet that uses .union() to combine the values of the sets consonants and vowels.

Use print() to output alphabet.

Folder Icon

Take this course for free

Already have an account?