Swift version: 5.1
The ternary operator allows you to run a check and return one of two values depending on the result of that check – it has the name “ternary” because it works with three values rather than two or one like other operators. You’ll often see it written as
?: but in practice the
: are used separately.
Like I said, the ternary operator is used with three values: the check to run, what to return if the check is true, and what to return if the check is false. For example, if we had a
score constant that contained an integer, we could make a
result constant equal either to “Pass” or “Fail” depending on the value of
let score = 88 let result = score > 85 ? "Pass" : "Fail"
You can read that ternary as “if score is greater than 85 return Pass otherwise return Fail.” Because
score was set to 88,
result will be set to Pass.
The ternary operator usually makes your code harder to read and understand, so it doesn’t get much use.
LEARN SWIFTUI FOR FREE I have a massive, free SwiftUI video collection on YouTube teaching you how to build complete apps with SwiftUI – check it out!
Available from iOS 8.0
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.