Swift中的函数常见写法
这里不涉及函数作为参数和返回值的情况。
进军iOS开发了哈。
计划六一前，搞一个套H5的App出来,
靠谱么？
其实，看过了java,php,javascript,python,go之后，
再在看swift，感觉很亲切啊，
都是老熟人。
func greet(person: String) -> String {
let greeting = "Hello, " + person + "!"
return greeting
}
print(greet(person: "Anna"))
print(greet(person: "Brian"))
func sayHelloWorld() -> String {
return "hello, world"
}
print(sayHelloWorld())
func greet2(person: String) {
print("Hello, \(person)!")
}
greet2(person: "Dave")
func printAndCount(string: String) -> Int {
print(string)
return string.characters.count
}
func printWithoutCounting(string: String) {
let _ = printAndCount(string: string)
}
printAndCount(string: "Hello, world")
printWithoutCounting(string: "Hello, world")
func minMax(array: [Int]) -> (min: Int, max: Int)? {
if array.isEmpty {return nil}
var currentMin = array[0]
var currentMax = array[0]
for value in array[1..<array.count] {
if value < currentMin {
currentMin = value
} else if value > currentMax {
currentMax = value
}
}
return (currentMin, currentMax)
}
if let bounds = minMax(array: [8, -6, 2, 109, 3, 71]) {
print("min is \(bounds.min) and max is \(bounds.max)")
}
func gt(person: String, from hometown: String) -> String {
return "Hello \(person)! glad you could visit from \(hometown)."
}
print(gt(person: "Bill", from: "Cupertino"))
func someFunc(_ firstP: Int, secondP: Int) {
print(firstP + secondP)
}
someFunc(1, secondP: 5)
func someFunc2(pWithoutD: Int, pWithD: Int = 12) {
print(pWithoutD + pWithD)
}
someFunc2(pWithoutD: 5)
func arithmeticMean(_ numbers: Double...) -> Double {
var total: Double = 0
for number in numbers {
total += number
}
return total / Double(numbers.count)
}
print(arithmeticMean(1, 2, 3, 4, 5))
print(arithmeticMean(3, 5.34, 12.38, 67, 21.97))
func swapTwoInts(_ a: inout Int, _ b: inout Int) {
let temporaryA = a;
a = b
b = temporaryA
}
var someInt = 3
var anotherInt = 107
swapTwoInts(&someInt, &anotherInt)
print("someInt is now \(someInt), and anotherInt is now \(anotherInt)")
