Optionals are used when a value cannot be set. Think of optionals as a container, which can take either a value or nil. This gives us the ability to check whether the value is nil or not. In order to create an optional value, you will have to give it a data type followed by a question mark (?). Before we do that, let's create a string that is not an optional. Add the following to Playgrounds:
var strNotAnOptional = "This is not an optional"
Now, let's add an optional to Playgrounds:
var strOptional:String?
In this example, we created a string optional, and, if you notice in the Results panel, it is nil. But for our strNotAnOptional, we see This is not an optional. Now, on the next line, let's set strOptional equal to This is an optional:
strOptional = "This is an optional"
In our Results panel, we see This is an optional. Let's now print both strNotAnOptional and strOptional, as you will see a difference between the two:
print(strNotAnOptional) print(strOptional...