Swift中的闭包例子

常见的实现，

要熟悉了解，

至于闭包逃逸，

自动闭包这些内容，

可以以后用到时再学吧。

let names = ["Chris", "Alex", "Eva", "Barry", "Daniella"]


func backward(_ s1: String, _ s2: String) -> Bool {
	return s1 < s2
}
var rNames = names.sorted(by: backward)
rNames = names.sorted(by: {(s1: String, s2: String) -> Bool in 
	return s1 > s2
})
rNames = names.sorted(by: {(s1: String, s2: String) -> Bool in return s1 > s2})
rNames = names.sorted(by: {s1, s2 in return s1 > s2})
rNames = names.sorted(by: {s1, s2 in s1 > s2})
rNames = names.sorted(by: {$0 > $1})
rNames = names.sorted(by: >)
rNames = names.sorted(){$0 > $1}
rNames = names.sorted{$0 > $1}

print(rNames)

let digitNames =  [
	0: "Zero", 1: "One", 2: "Two", 3: "Three", 4: "Four",
	5: "Five", 6: "Six", 7: "Seven", 8: "Eight", 9: "Nine"
]

let numbers = [16, 58, 510]

let strings = numbers.map {
	(number) -> String in 
	var number = number
	var output = ""
	repeat {
		output = digitNames[number % 10]! + output
		number /= 10
	} while number > 0
	return output
}

print(strings)

func makeIncrementer(forIncrement amount: Int) -> () -> Int {
	var runningTotal = 0
	func incrementer() -> Int {
		runningTotal += amount
		return runningTotal
	}
	return incrementer
}

let incrementByTen = makeIncrementer(forIncrement: 10)
print(incrementByTen())
print(incrementByTen())
print(incrementByTen())
print(incrementByTen())