ctx.res.setHeader('Cache-control', 'public,max-age=86400')

  let exp = new Date()
  exp.setTime(exp.getTime() + 60000)//毫秒
  ctx.res.setHeader('Expires', exp.toUTCString())
  ctx.res.setHeader('Cache-control', 'public,max-age=86400')//秒

let arr = [2, 3, 4, 1, 8]
arr.sort(function (a, b) {
  return a - b
})

let arr = [2, 3, 4, 1, 8]
arr.sort((a, b) => a - b)

let f = () => console.log(1)
f()

let a = 1
let f = a => console.log(a)

f(a)

let a = 1,
  b = 2
let f = (a, b) => console.log(a + b)

f(a, b)

let a = 1,
  b = 2
let f = (a, b) => a + b
//等价于以下代码
let g = (a, b) =>{return  a + b}
console.log(g(a, b))
console.log(f(a, b))

let a = 1,
  b = 2

let g = (a, b) => void (a + b)
let f = (a, b) => a + b

console.log(g(a, b), f(a, b))

let a = 1,
  b = 2

let g = (a, b) => {
  let c = 4
  return a + b + c
}
console.log(g(a, b))

var id = 'apple'
var obj = {
  id: 'obj',
  a: function () {
    console.log(this.id)
  },
  b: () => {
    console.log(this.id)
    return
  }
}

obj.a()
obj.b()

exports.id = 'apple'
var obj = {
  id: 'obj',
  a: function () {
    console.log(this.id)
  },
  b: () => {
    console.log(this.id)
    return
  }
}

obj.a()
obj.b()

if(""){
  console.log('true')
}

let str = 'abcdefg'
for (let i = 0; i < str.length; i++) {
  str[i] = 'A'
}
console.log(str)//abcdefg

let a={name:'a'}
let b={name:'a'}
a==b//false
a==a//true

function name(params) {}
console.log(typeof name.prototype)//object

let a = { name: 'A' }

let b = { name: 'B' }

Object.prototype.say = function () {
  console.log(this.name)
}

a.say() //A
b.say() //B

function apple() {
  this.name = 'apple'
}

let a = new apple()

console.log(a.__proto__ === apple.prototype)//true

function apple() {
  this.name = 'apple'
}

let a = new apple()

//读
console.log(Object.getPrototypeOf(a) === a.__proto__)

//写
a.__proto__ = Object.prototype

Object.setPrototypeOf(a, apple.prototype)

//创建
let b = Object.create(apple.prototype)

function apple() {
  this.name = 'apple'
}

let a = new apple()

console.log(a instanceof apple)//true

function apple() {
  this.name = 'apple'
}

let a = new apple()

console.log(apple.prototype.isPrototypeOf(a)) //true

let a = {}
console.log(a instanceof Object)//true

function apple() {
  this.name = 'apple'
}

let a = new apple()

console.log(a instanceof apple)//true
console.log(a instanceof Object)//true

var obj = {}//1
obj.__proto__ = F.prototype//2
F.call(obj)//3
return obj//4

console.log(Object.prototype.__proto__)//null

let a = { name: 'A' }

let b = { name: 'B' }

Object.prototype.say = function () {
  console.log(this.name)
}

console.log(a.hasOwnProperty('name'))

console.log(a.hasOwnProperty('say'))

Object.prototype.bar = 1;

var foo = {
    moo: 2
};
for(var i in foo) {
    console.log(i); 
}

let num = '1234'
let arr = num.split('')

console.log(num instanceof String)//false

var Morris_pre = function (root) {
  if (!root) return
  let curr = root
  while (curr) {
    if (curr.left) {
      let proNode = curr.left
      while (proNode.right && proNode.right !== curr) {
        proNode = proNode.right
      }
      if (!proNode.right) {
        console.log(curr.val)
        proNode.right = curr
        curr = curr.left
      } else {
        curr = curr.right
        proNode.right = null
      }
    } else {
      console.log(curr.val)
      curr = curr.right
    }
  }
}

var Morris_mid = function (root) {
  if (!root) return
  let curr = root
  while (curr) {
    if (curr.left) {
      let proNode = curr.left
      while (proNode.right && proNode.right !== curr) {
        proNode = proNode.right
      }
      if (!proNode.right) {
        proNode.right = curr
        curr = curr.left
      } else {
        console.log(curr.val)
        curr = curr.right
        proNode.right = null
      }
    } else {
      console.log(curr.val)
      curr = curr.right
    }
  }
}

var Morris_post = function (root) {
  if (!root) return
  let curr = root
  while (curr) {
    if (curr.left) {
      let proNode = curr.left
      while (proNode.right && proNode.right !== curr) {
        proNode = proNode.right
      }
      if (!proNode.right) {
        proNode.right = curr
        curr = curr.left
        continue
      } else {
        proNode.right = null
        print(curr.left)
      }
    }
    curr = curr.right
  }
  print(root)
}

function print(node) {
  const tail = reverse(node)
  let temp = tail
  while (temp) {
    console.log(temp.val)
    temp = temp.right
  }
  reverse(tail)
}

function reverse(node) {
  let pre, next
  while (node) {
    ;[next, node.right] = [node.right, pre]
    ;[pre, node] = [node, next]
  }
  return pre
}

if (false) {
  var a = 'ybf'
}

console.log(a)//undefined

var a
function a() {}

console.log(a)//function...

function a(a1, b1) {
  
  function a1() {}
  console.log(a1)
}

a('a传参', 'b传参')//function a1() { … }

function name() {
  var a = b = 'ybf'
}
name()
// console.log(a)//is not defined
console.log(b)//"ybf"

function a(a1, b1) {
  console.log(a1)//function

  var a1 = 'var'
  console.log(a1)//var

  function a1() {}
  console.log(a1)//var
}

a('a传参', 'b传参') 

var a //undfined

var a = null

function curry(fn) {
  var args = Array.prototype.slice.call(arguments, 1)
  return function () {
    var innerArgs = Array.prototype.slice.call(arguments)
    var finalArgs = args.concat(innerArgs)
    return fn.apply(null, finalArgs)
  }
}

function add(num1, num2) {
  return num1 + num2
}

var curriedAdd = curry(add, 5)

console.log(curriedAdd(3)) //8

var singleNonDuplicate = function (nums) {
  if (nums.length === 0) return null
  let left = 0
  let right = nums.length - 1
  while (left <= right) {

    if (left === right) return nums[left]

    let mid = (left + right) >> 1
    if (nums[mid] === nums[mid - 1]) {
      if ((mid - left - 1) % 2 === 1) {
        right = mid - 2
      } else {
        left = mid + 1
      }
    } else if (nums[mid] === nums[mid + 1]) {
      if ((right - mid - 1) % 2 === 1) {
        left = mid + 2
      } else {
        right = mid - 1
      }
    } else {
      return nums[mid]
    }
  }
}

Function.prototype.mybind = function () {
	var slice = Array.prototype.slice
	var thatFunc = this,
		thatArg = arguments[0]
	var args = slice.call(arguments, 1)
	if (typeof thatFunc !== 'function') {
		// closest thing possible to the ECMAScript 5
		// internal IsCallable function
		throw new TypeError(
			'Function.prototype.bind - ' +
				'what is trying to be bound is not callable'
		)
	}
	return function () {
		var funcArgs = args.concat(slice.call(arguments))
		return thatFunc.apply(thatArg, funcArgs)
	}
}
Function.prototype.mycall = function (context, ...args) {
	if (!context) {
		console.log('不存在')
		context = global
	}
	if (typeof context !== 'object') {
		console.log('不是对象')
		context = global
	}
	let say = Symbol() // 防止覆盖掉原有属性
	context[say] = this // 这里的this为需要执行的方法
	const res = context[say](...args)
	delete context[say]
	return res
}

var fun = Function.prototype.mycall(Object.prototype.toString)

Object.prototype.toString.Function.prototype()

var toStr1 = Function.prototype.mycall.mycall(Object.prototype.toString)

Object.prototype.toString.mycall()

Object.prototype.toString.call(global)

var toStr1 = Function.prototype.mycall.mybind(Object.prototype.toString)

Function.prototype.mycall.myapply(Object.prototype.toString, [[123]])

let apple = {
  name: 'apple',
  test: function (price, time) {
    console.log(time, this.name, price)
  }
}
let pear = {
  name: 'pear'
}
//在原型链上绑定方法
Function.prototype._call = function (context, ...args) {
  if (!context || typeof context !== 'object') {
    context = global
  }
  let say = Symbol() // 防止覆盖掉原有属性
  context[say] = this // 这里的this为需要执行的方法
  const res = context[say](...args)
  delete context[say]
  return res
}
apple.test._call(pear, 10, '2020-5-29')//2020-5-29 pear 10

let apple = {
  name: 'apple',
  test: function (price, time) {
    console.log(time, this.name, price)
  }
}
let pear = {
  name: 'pear'
}
global.name = 'window'//环境为node
apple.test.apply(null, [10, '2020-5-29'])//2020-5-29 window 10

Function.prototype._apply = function (context, args) {
  if (!context || typeof context !== 'object') {
    context = global
  }
  const key = global.Symbol() // 防止覆盖掉原有属性
  context[key] = this // 这里的this为需要执行的方法
  const result = context[key](...args)
  delete context[key]
  return result
}
apple.test._apply(null, [10, '2020-5-29'])//2020-5-29 window 10

apple.test._apply(pear, [10, '2020-5-29']) //2020-5-29 pear 10

let apple = {
  name: 'apple',
  test: function (price, time) {
    console.log(time, this.name, price)
  }
}
let pear = {
  name: 'pear'
}

//借助call
Function.prototype._bind = function (context) {
  if (!context || typeof context !== 'object') {
    context = global
  }
  return (...args) => {
    this.call(context, ...args)
  }
}
let fun1 = apple.test._bind(pear)
fun1(10, '2020-5-29') //2020-5-29 pear 10

let apple = {
  name: 'apple',
  test: function (price, time) {
    console.log(time, this.name, price)
  }
}
let pear = {
  name: 'pear'
}
Function.prototype._call = function (context, ...args) {
  if (!context || typeof context !== 'object') {
    context = global
  }
  let say = Symbol() // 防止覆盖掉原有属性
  context[say] = this // 这里的this为需要执行的方法
  const res = context[say](...args)
  delete context[say]
  return res
}

//不使用原生call
Function.prototype._bind_ = function (context) {
  if (!context || typeof context !== 'object') {
    context = global
  }
  return (...args) => {
    this._call(context, ...args)
  }
}

let fun2 = apple.test._bind_(pear)
fun2(10, '2020-5-29') //2020-5-29 pear 10

export default function debounce(fun, delay) {
  let timer
  return function(...args) {
    if (timer) {
      clearTimeout(timer)
    }
    timer = setTimeout(() => {
      fun.apply(this, args)
    }, delay)
  }
}

/**
 * @param {string} s
 * @return {string}
 */
var decodeString = function (s) {
  //得到数字和字符串
  let reg = /(\d+)\[([a-zA-Z]+)\]/g
  //检测是否完成
  let all = /\[.*\]/
  //循环直到完成编码
  while (all.test(s)) {
    s = s.replace(reg, (match, p1, p2) => p2.repeat(~~p1))
  }
  return s
}

作者：ybf20181212
链接：https://leetcode-cn.com/problems/decode-string/solution/jszheng-ze-by-ybf20181212/
来源：力扣（LeetCode）
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

var decodeString = s => {
  let stack_num = []
  let stack_str = []
  let num = 0
  let res = ''
  for (const char of s) {
    if (!isNaN(char)) {
      num = num * 10 + ~~char
    } else if (char === '[') {
      stack_num.push(num)
      stack_str.push(res)
      res = ''
      num = 0
    } else if (char === ']') {
      res = stack_str.pop() + res.repeat(stack_num.pop())
    } else {
      res += char
    }
  }
  return res
}

class AVLNode {
  constructor(val) {
    this.val = val
    this.left = null
    this.right = null
    this.height = 1
  }
  getKey() {}
}
const BLANCE_STATE = {
  UNBALANCE_LEFT: 2,
  UNBALANCE_RIGHT: -2,
  SLIGHT_UNBALANCE_LEFT: 1,
  SLIGHT_UNBALANCE_RIGHT: -1,
  BALANCE: 0
}
class AVLTree {
  constructor() {
    this.root = null
  }
  //RR
  _leftRotate(node) {
    const res = node.right
    ;[res.left, node.right] = [node, res.left]
    this._updateHeigh(node)
    return res
  }
  //LL
  _rightRotate(node) {
    const res = node.left
    ;[res.right, node.left] = [node, res.right]
    this._updateHeigh(node)
    return res
  }

  //LR
  _leftRightRotate(node) {
    node.left = this._updateHeigh(this._leftRotate(node.left))
    return this._rightRotate(node)
  }
  //RL
  _rightLeftRotate(node) {
    node.right = this._updateHeigh(this._rightRotate(node.right))
    return this._leftRotate(node)
  }
  _getHeight(node) {
    return node !== null ? node.height : 0
  }
  _updateHeigh(node) {
    node.height =
      Math.max(this._getHeight(node.left), this._getHeight(node.right)) + 1
    return node
  }
  insert(val) {
    this.root = this._insertNode(this.root, val)
  }
  _insertNode(node, val) {
    if (node === null) return new AVLNode(val)
    if (node.val === val) return node
    if (node.val < val) {
      node.right = this._insertNode(node.right, val)
    } else if (node.val > val) {
      node.left = this._insertNode(node.left, val)
    }
    return this._toBalance(node)
  }
  _toBalance(node) {
    if (node === null) return null
    const BalanceState = this._getBalanceState(node)

    if (BalanceState === BLANCE_STATE.UNBALANCE_LEFT) {
      const leftNodeBalanceState = this._getBalanceState(node.left)
      if (leftNodeBalanceState == BLANCE_STATE.SLIGHT_UNBALANCE_RIGHT) {
        return this._updateHeigh(this._leftRightRotate(node))
      } else {
        return this._updateHeigh(this._rightRotate(node))
      }
    } else if (BalanceState === BLANCE_STATE.UNBALANCE_RIGHT) {
      const rightNodeBalanceState = this._getBalanceState(node.right)
      if (rightNodeBalanceState == BLANCE_STATE.SLIGHT_UNBALANCE_LEFT) {
        return this._updateHeigh(this._rightLeftRotate(node))
      } else {
        return this._updateHeigh(this._leftRotate(node))
      }
    }
    return this._updateHeigh(node)
  }
  _getBalanceState(node) {
    return this._getHeight(node.left) - this._getHeight(node.right)
  }
  remove(val) {
    if (this.search(val) === null) return false
    this.root = this._removeNode(this.root, val)
    return true
  }
  _removeNode(node, val) {
    if (node.val > val) node.left = this._removeNode(node.left, val)
    else if (node.val < val) node.right = this._removeNode(node.right, val)
    else if (node.val == val) {
      if (node.left == null) return node.right
      else if (node.right == null) return node.left
      else {
        let next = this.getNext(val)
        node.val = next.val
        // 转为删除next节点
        node.right = this._removeNode(node.right, node.val)
      }
    }
    return this._doBalance(node)
  }
  search(val) {
    let node = this.root
    while (node) {
      if (node.val === val) return node
      else if (node.val > val) node = node.right
      else node = node.left
    }
    return null
  }
  getNext(val) {
    let res = null,
      node = this.root
    while (node) {
      if (node.val <= val) node = node.right
      else if (node.val > val) {
        res = node
        node = node.left
      }
    }
    return res
  }
}

function arrayToBBST(nums) {
  let avlTree = new AVLTree()
  for (let i = 0; i < nums.length; i++) {
    avlTree.insert(nums[i])
  }
  return avlTree
}

let a = [1, 2, '11']

Array.prototype._forEach = function (fn, thisArg) {
	//类型判断

	const list = this
	for (let i = 0; i < list.length; i++) {
		fn.call(this, list[i], i, arr)
	}
}

function n() {
	a._forEach((v, i) => {
		console.log(v)
		return
	})
}
n()

function setCookie(name, value) {
  document.cookie = name + "=" + value
}
for (let i = 1; i <= 300; i++) {
  setCookie(i + 'cookie', "value" + i);
}
console.log(document.cookie.split(" ").length)

console.log(encodeURIComponent("yyy,y;=y y"));//yyy%2Cy%3B%3Dy%20y
console.log(escape("yyy,y;=y y"));//yyy%2Cy%3B%3Dy%20y

console.log(decodeURIComponent("yyy%2Cy%3B%3Dy%20y"));//yyy,y;=y y
console.log(unescape('yyy%2Cy%3B%3Dy%20y'));//yyy,y;=y y

function setcookie(name, value, time, path, domain) {
  let exp = new Date();
  exp.setTime(exp.getTime() + time);
  document.cookie = name + "=" + escape(value) + ";expires=" + exp.getUTCDate() + ";path=" + path + ";domain=" + domain;
}
setcookie("age", "18", 6400, '/', "ybf.com")

ctx.cookies.set('id', 'apply', {
    httpOnly: false
  })
ctx.cookies.set('name', 'xiaomin', {
    httpOnly: true
})

ctx.cookies.get('age')

; (function (name, value, time, path, domain) {
  let exp = new Date();
  exp.setTime(exp.getTime() + time);
  document.cookie = name + "=" + value + ";expires=" + exp.toUTCString() + ";path=" + path + ";domain=" + domain;
})("ybf", "ybf", 86400000, '/', "ybf.com")

; (function (name, value, time, path, domain) {
  let exp = new Date();
  exp.setTime(exp.getTime() + time);
  document.cookie = name + "=" + value + ";expires=" + exp.toUTCString() + ";path=" + path + ";domain=" + domain;
})("acc", "acc", 86400000, '/', "acc.com")

  ctx.Cookies.set('ybf', 'ybf', {
    maxAge: 86400000,
    domain: 'ybf.com',
    httpOnly: false
  })
  ctx.Cookies.set('acc', 'acc', {
    maxAge: 86400000,
    domain: 'acc.com',
    httpOnly: false
  })

; (function (name, value, time, path, domain) {
  let exp = new Date();
  exp.setTime(exp.getTime() + time);
  document.Cookie = name + "=" + value + ";expires=" + exp.toUTCString() + ";path=" + path + ";domain=" + domain;
})("ybf", "ybf", 86400000, '/', "ybf.com")

; (function (name, value, time, path, domain) {
  let exp = new Date();
  exp.setTime(exp.getTime() + time);
  document.cookie = name + "=" + value + ";expires=" + exp.toUTCString() + ";path=" + path + ";domain=" + domain;
})("ybf", "ybf", 86400000, '/', "test.ybf.com")

var a = { name: '1' }
console.log(a)//已经挂载在全局变量上

function name(params) {
  var a = { name: '1' }
  b = a
}
name()
console.log(b)//已经挂载在全局变量上

function A() {
  var a = '函数内部'
  console.log(a)//'函数内部'
}
A()
console.log(a)//报错

for(var i = 0; i < 5; i++) {
  setTimeout(function() {
     console.log(i);			// 5 5 5 5 5
  }, 200);
};

for (let i = 0; i < 5; i++) {
  setTimeout(function () {
    console.log(i) // 0 1 2 3 4
  }, 200)
}

function foo(){
    console.log(a);
}

function bar(){
    var a = 3;
    foo();
}

var a = 2;

bar();//答案是？

let obj = {
  a: 'a',
  b: 'b',
  c: {
    c1: 'c1',
    c2: 'c2'
  }
}

function copy(object) {
  let _obj = {}
  for (const key of Object.keys(obj)) {
    _obj[key] = object[key]
  }
  return _obj
}

let temp = copy(obj)

temp.c.c1 = 'test'

console.log(obj.c.c1)//test
console.log(temp.c.c1)//test

function A() {
  this.a = 'A'
}
A.prototype.YBF = function (params) {}

let a = new A()
let aa = JSON.parse(JSON.stringify(a))

let obj1 = { name: 'obj1' }
let obj2 = { name: 'obj2' }
obj1.a = obj2
obj2.a = obj1

let obj3 = {
  b: obj1
}
JSON.parse(JSON.stringify(obj3))

let list = [1, 1, 1, 1]
let set = new Set(list)
let rex = new RegExp('adb')
let map = new Map([{ 1: 1 }, { 2: 2 }])

let a = {
  list: list,
  set: set,
  rex: rex,
  map: map
}
let aa = JSON.parse(JSON.stringify(a))

const isType = (obj, type) => {
  if (typeof obj !== 'object') return false
  const typeString = Object.prototype.toString.call(obj)
  let flag
  switch (type) {
    case 'Array':
      flag = typeString === '[object Array]'
      break
    case 'Set':
      flag = typeString === '[object Set]'
      break
    case 'Map':
      flag = typeString === '[object Map]'
      break
    default:
      flag = false
  }
  return flag
}

const deepClone = parent => {
  const hasClone = new Set()
  const _deepClone = parent => {
    if (parent === null) return null
    if (hasClone.has(parent)) {
      return parent
    }
    if (typeof parent !== 'object') return parent
    let child
    hasClone.add(parent)
    if (isType(parent, 'Array')) {
      child = []
      for (const iterator of parent) {
        child.push(_deepClone(iterator))
      }
    } else if (isType(parent, 'Map')) {
      child = new Map()
      for (const [key, value] of parent) {
        child.set(key, _deepClone(value))
      }
    } else if (isType(parent, 'Set')) {
      child = new Set()
      for (const iterator of parent) {
        child.add(_deepClone(iterator))
      }
    } else {
      proto = Object.getPrototypeOf(parent)
      child = Object.create(proto)
      for (const key in parent) {
        child[key] = _deepClone(parent[key])
      }
    }
    return child
  }
  return _deepClone(parent)
}