Imagine walking through an art museum and finding two identical Mona Lisa paintings hanging on the wall. That situation would most likely cause a few raised eyebrows. Art museums should only contain unique content, like a set does in Swift.
A set is an unordered collection of unique elements.
There are many similarities between sets and arrays, but the main differences between the two are:
- Set elements cannot be repeated, while that is allowed in arrays.
- A set does not have a defined order, while an array does.
Sets are a great collection type to use when the data we need to store must be unique.
For example, we could use a set in real life to store information about employee ID numbers at a company or to store bank account numbers.
In this lesson, we will learn how to create and use sets in Swift.
Instructions
Take a look at the image to the right.
When the unique item, "T" tries to join the group of letters, it is allowed in; however, when a second "S" attempts to join the set of letters, it is not allowed in because an "S" item already exists.
When you’re all set, click Next to continue.