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15 Swift Task

Posted on Edited on In

Closure


Optimize clousre

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let someClosure: (String, String) -> Bool = { (s1: String, s2: String) -> Bool in
    let isAscending: Bool

    if s1 > s2 {
        isAscending = true
    } else {
        isAscending = false
    }

    return isAscending
}

let optimizedSomeClosure: (String, String) -> Bool = { $0 > $1 }

someClosure("apple", "banana")
// false
optimizedSomeClosure("apple", "banana")
// false

someClosure("banana", "apple")
// ture
optimizedSomeClosure("banana", "apple")
// ture

let otherClosure: ([Int]) -> Int = { (values: [Int]) -> Int in
    var count: Int = 0
    for _ in values {
        count += 1
    }
    return count
}

let optimizedOtherClosure: ([Int]) -> Int = { $0.count }

otherClosure([0, 1, 2, 3, 4])
optimizedOtherClosure([0, 1, 2, 3, 4])

otherClosure([0])
optimizedOtherClosure([0])

These functions might seem work differently but short form of closures are just optimized so they return same value.