loop-vs-filter.swift

func measure(block : () -> ()) -> NSTimeInterval {
    var averages = [NSTimeInterval]()
    for _ in 1...1000 {
        let date = NSDate()
        block()
        averages.append(NSDate().timeIntervalSinceDate(date))
    }
    return averages.reduce(0, combine: +) / Double(averages.count)
}

let filterAverage = measure {
    let arr = ["a", "b", "c", "b"]
    let farray = arr.filter {$0 != "b"}
}

// http://stackoverflow.com/a/33722186/1445366
let loopAverage = measure {
    var Array : [String]
    Array = ["a", "b", "c", "b"]
    
    let itemToRemove = "b"
    
    while Array.contains(itemToRemove){
        if let itemToRemoveIndex = Array.indexOf(itemToRemove){
            Array.removeAtIndex(itemToRemoveIndex)
        }
    }
}


// percentage increase
(filterAverage - loopAverage) / loopAverage