Instance MethodSwift
first(where:)
Returns the first element of the sequence that satisfies the given predicate.
func first(where predicate: (Self.Element) throws -> Bool) rethrows -> Self.Element?Parameters
- predicate
A closure that takes an element of the sequence as its argument and returns a Boolean value indicating whether the element is a match.
Returns
The first element of the sequence that satisfies predicate, or nil if there is no element that satisfies predicate.
Overview
The following example uses the first(where:) method to find the first negative number in an array of integers:
let numbers = [3, 7, 4, -2, 9, -6, 10, 1]
if let firstNegative = numbers.first(where: { $0 < 0 }) {
print("The first negative number is \(firstNegative).")
}
// Prints "The first negative number is -2."