闭包

let cs = {
    (a: Int, b:Int) in
    
    return a + b
}//创建一个闭包，参数类型要么前面说明，要么在里面创说明
let ss = cs (1,2)//调用，进行传值
print(ss)



func es (a:Int, b :Int, c:(Int,Int)->Int) ->Int{
    return c(a,b)
}//创建一个有闭包参数的函数


let pp = es(11, b: 34, c: cs)
print(pp)



var arr1 = [1,3,2,5]
var arr2 = arr1
    .map({$0*$0})//将数组中的元素进行平方
    .filter({$0>3})//筛选arr1大于3
    .map({"\($0)"})//将数组元素转换为字符串类型
    .reduce("", combine: {$0+$1})//将字符串连接起来
print(arr2)
let kk:(q:Int, w:Int)->Int = {
    q,w in
    return q+w
}
let ww = kk(q: 1,w: 2)//对闭包进行传值
print(ww)



let uu = {
    () -> Int in
    return 33
}() //执行闭包
print(uu)


func test1(a:Int) -> (Int)->(Int)->Int{
    var b=3
    return {
        print("二层",$0,a,b)
            //return $0+a+b
        return{
            print("三层",$0,a,b)
            return $0+a+b
        }
    }
}

let ss2 = test1(33)(3)(44)//三层调用闭包
print(ss2)

用代码实现之前的猜数字的功能和界面

import UIKit

class ViewController: UIViewController {
    var result = arc4random_uniform(100)//生成一个100以内的随机数
    let label1 = UILabel()
    let textfield = UITextField()
    override func viewDidLoad() {
        super.viewDidLoad()
        //史上最强猜数字框
        let label = UILabel()
        label.frame = CGRectMake(60, 30, 200, 50)
        label.backgroundColor = UIColor.brownColor()
        label.text = "史上最强猜数字"
        label.textAlignment = .Center//文本框内容字对齐
        self.view.addSubview(label)
        
        //结果输出框
        label1.frame = CGRectMake(60, 300, 200, 50)
        label1.text = "结果为："
        label1.backgroundColor = UIColor.blueColor()
        label1.textAlignment = .Center
        self.view.addSubview(label1)
        
        
        //数字0
        let label2 = UILabel()
        label2.frame = CGRectMake(90, 90, 30, 50)
        label2.text = "0"
        label2.backgroundColor = UIColor.greenColor()
        label2.textAlignment = .Center
        self.view.addSubview(label2)
        
        
        //数字100
        let label3 = UILabel()
        label3.frame = CGRectMake(190, 90, 30, 50)
        label3.text = "100"
        label3.backgroundColor = UIColor.greenColor()
        label3.textAlignment = .Center
        self.view.addSubview(label3)
        
        
        //到
        let label4 = UILabel()
        label4.frame = CGRectMake(140, 90, 30, 50)
        label4.text = "到"
        label4.backgroundColor = UIColor.cyanColor()
        label4.textAlignment = .Center
        self.view.addSubview(label4)
        
        
        //输入文本框
        textfield.frame = CGRectMake(60, 150, 200, 50)
        textfield.backgroundColor = UIColor.redColor()
        textfield.keyboardType = UIKeyboardType.NumbersAndPunctuation//设置键盘类型
        textfield.borderStyle = .RoundedRect//设置圆边框
        textfield.placeholder = "请输入内容"
        textfield.clearsOnBeginEditing = true//清除上一次的输入
        textfield.clearButtonMode = .WhileEditing//设置输入框的清除按钮
        textfield.font = UIFont.boldSystemFontOfSize(30)//设置字体大小
        self.view.addSubview(textfield)
    
        //确定按钮
        let but = UIButton(type:.System)
        but.frame = CGRectMake(110, 220, 100, 50)
        but.backgroundColor = UIColor.greenColor()
        but.setTitle("确定", forState: .Normal)
        but.setTitle("选中", forState: .Selected)
        //let image = UIImage(named: "check")
        //let image1 = UIImage(named: "check1")
        //but.setBackgroundImage(image, forState: .Normal)
        //but.setBackgroundImage(image1, forState: .Selected)
        self.view.addSubview(but)
        //添加触碰事件动作
        but.addTarget(self, action: #selector(DidClick), forControlEvents: .TouchUpInside)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func DidClick(){//定义点击调用的函数
        let guess = UInt32(textfield.text!)
        print("猜测数字为",textfield.text)
        print("实际数字是：",result)
        if guess == result {
            label1.text = "猜对了"
        }
        else if guess > result{
            label1.text = "不好意思，数字大了"
        }else {
            label1.text = "不好意思，数字小了"
        }
        
    }
    //设置点击屏幕空白处，发生第一响应，撤销键盘
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        
        self.view.endEditing(true)
    }
}