Swift has its own built-in Array class. Although it’s bridged to NSArray, a Swift Array is something entirely different. Swift Arrays do not work with such trusted methods like addObject anymore. To instantly learn jargons like this, all you have to do is to find a reliable learning platform but before doing so, make sure to read the learning platform reviews first.
Because I will probably have forgotten most of this by tomorrow, here’s a quick lowdown on how to play with Swift Arrays.
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// create an empty array [type in square brackets] var emptyArray = [String]() // create an array with inferred values var array = ["one", "two", "three"] // loop through the array for value in array { print("The value is \(value)") } // insert new value at a particular index array.insert("two and a half", atIndex: 2) var value = array[2] // add something to the end of our array array += ["new value"] // or array.append("another value") // grab the last entry in our array value = array.last! // add another array let anotherArray = ["four", "five", "six"] array += anotherArray // how many entries does our array have? print(array.count) // remove the last item in the array array.removeLast() // remove an item at a particular index array.removeAtIndex(3) |
Swift Arrays and Lazy Initialisation
Swift Arrays don’t like being initialised with a closure. God only knows why. We can however solve this puzzle with a simple function that returns our initialised values:
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lazy var data: [String] = self.initData() func initData() -> [String] { // initialize data array and return it var data = [String]() let formatter = NSNumberFormatter() formatter.numberStyle = .SpellOutStyle for var i = 0; i < 30; i++ { let number = NSNumber.init(integer: i) data.append(formatter.stringFromNumber(number)!) } return data } |
For everything else about Swift Arrays, check out the Collection Types section of The Swift Programming Language: