Useful Swift Tips and Tricks

swiftTips.swift

// This is a list of nice tips and tricks I discovered

//MARK: Tip #1

let task = urlSession.dataTask(with: url) { data, _, error
    
    switch error {
    case .error(let error as NSError) where error.code == NSURLErrorNotConnectedToInternet:
        presenter.showOfflneError()
    case .error(let error):
        presenter.showNetworkTaskError(with: error)
    case .noError()
        presenter.displayData(data)
    }
}

//In swift 3 NSError domains and codes can be used for pattern matching
//MARK: Tip #2

let task = urlSession.dataTask(with: url) { data, _, error
    
    if let error = error {
        switch error {
        case URLError.notConnectedToInternet:
            presenter.showOfflneError()
        case .error(let error):
            presenter.showNetworkTaskError(with: error)
        }
    }
    
    presenter.displayData(data)
}

//MARK: Tip #3
// Convert String to Data
let string = "String"
let data = string.data(using:.utf8)
// cleaner way
let data = Data(string.utf8)


//MARK: Tip #3
//elementsEqual() on unordered collections uses elemetns order for comparison

var set_1: Set<Int> = Set(1...5)
var set_2: Set<Int> = Set(1...5).reversed()

set_1==set_2 // true
set_1.elementsEqual(set_2) // false