const square = {
  distance: 5,
  getArea() {
    return square.distance ** 2
  },
}

console.log(square.getArea())

const square1 = {
  distance: 5,
  getArea() {
    return this.distance ** 2
  },
}

function ProtoSquare(distance) {
  this.distance = distance
}
ProtoSquare.prototype.getArea = function () {
  return this.distance ** 2
}

const square2 = new ProtoSquare(5)
console.log(square2.getArea())

class ClassSquare {
  constructor(distance) {
    this.distance = distance
  }
  getArea() {
    return this.distance ** 2
  }
}

const square3 = new ClassSquare(5)
console.log(square3.getArea())

function hi() {
  console.log(this) //window 또는 global
}
hi()

var value = 1

const obj = {
  value: 100,
  foo() {
    setTimeout(function () {
      console.log(this) // window
      console.log(this.value) // 1
    }, 100)
  },
  too() {
    function bar() {
      console.log(this) // window
      console.log(this.value) // 1
    }
    bar()
  },
}

var value = 1

const obj = {
  value: 100,
  too() {
    "use strict"
    function bar() {
      console.log(this) // undefined
      console.log(this.value) // Uncaught TypeError: Cannot read properties of undefined
    }
    bar()
  },
}

obj.too()

const person = {
  name: "lee",
  getName() {
    return this.name
  },
}

console.log(person.getName()) //lee

const anotherPerson = {
  name: "kim",
}

anotherPerson.getName = person.getName
console.log(anotherPerson.getName()) //kim

const getName = person.getName
console.log(getName()) // window

function foo() {
  console.log(this.text)
}

var name = {
  text: "영준",
  foo: foo,
}

var person = {
  text: "가영",
  name: name,
}

person.name.foo()

function getThisBinding() {
  console.log(arguments)
  return this
}

const thisArg = { a: 1 }
console.log(getThisBinding())
console.log(getThisBinding.apply(thisArg, [1, 2, 3])) //[1, 2, 3]
console.log(getThisBinding.call(thisArg, 1, 2, 3)) //[1,2,3]

const person = {
  name: "lee",
  foo(callback) {
    setTimeout(callback.bind(this), 100)
  },
}

person.foo(function () {
  console.log(this.name) //lee
})

function foo() {
  this.name = "영준"
  this.callName = function () {
    console.log(this.name)
  }
}

const bar = {
  name: "주희",
}

const x = new foo()
x.callName.bind(bar)
x.callName() // 영준

function foo() {
  setTimeout(() => {
    console.log(this.name)
  }, 1000)
}

const bar = {
  name: "영준",
}

foo.call(bar) // 영준

const foo = {
  name: "영준",
  bar: () => console.log(this.name),
}

foo.bar() // undefined

const boo = {
  name: "영준",
  far() {
    console.log(this.name)
  },
}

boo.far() //영준