Returns the first index in which an element of the collection satisfies the given predicate.
- iOS 7.0+
- macOS 10.9+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Xcode 10.0+
A closure that takes an element as its argument and returns a Boolean value that indicates whether the passed element represents a match.
The index of the first element for which
true. If no elements in the collection satisfy the given predicate, returns
You can use the predicate to find an element of a type that doesn’t conform to the
Equatable protocol or to find an element that matches particular criteria. Here’s an example that finds a student name that begins with the letter “A”:
Complexity: O(n), where n is the length of the collection.