tgnivekucn

//用語言提供的基本語法找出陣列中的奇數和偶數
func test1(arr: [Int]) -> Void {
    for item in arr {
        if isOdd(val: item) {
            print("\(item)")
        }
    }
}
func test2(arr: [Int]) -> Void {
    for item in arr {

tgnivekucn

//用語言提供的基本語法
func test1(arr: [Int]) -> Void {
 for item in arr {
 if isOdd(val: item) {
 print("\(item)")
 }
 }
}
func test2(arr: [Int]) -> Void {
 for item in arr {

tgnivekucn

//ex: 比較 a,b大小
var a = 54
var b = 5
//用function:
func compare(val1: Int,val2: Int) -> Bool {
 return a > b
}
assert(compare(val1:a,val2:b), "error, a can not larger than b")
//用closure:
assert(a > b, "error, a can not larger than b") //note: a > b 即為closure,其省略了參數和回傳值

tgnivekucn

	func B(callback: @escaping (Bool) -> Void) {
		//step2
		DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 100) {//this 100s indicates long time task
			//step 3
			callback(true)
		}	
	}

	//step1
	func B {