count(where:)

About 2 min

count(where:) 관련

HACKING WITH SWIFT

What's new in Swift?

count(where:) | Changes in Swift 6.0

count(where:)

Available from Swift 6.0

SE-0220 (apple/swift-evolution) introduced a new count(where:) method that performs the equivalent of a filter() and count in a single pass. This saves the creation of a new array that gets immediately discarded, and provides a clear and concise solution to a common problem.

This example creates an array of test results, and counts how many are greater or equal to 85:

let scores = [100, 80, 85]
let passCount = scores.count { $0 >= 85 }

And this counts how many names in an array start with “Terry”:

let pythons = ["Eric Idle", "Graham Chapman", "John Cleese", "Michael Palin", "Terry Gilliam", "Terry Jones"]
let terryCount = pythons.count { $0.hasPrefix("Terry") }