code sample, this, statement,expression (class-6)

//Evolution of Function, function statement vs Expression
//first class function
//javascript "this"

//function statement
// function sum(num1, num2){
//   return num1 + num2
// }

//function expression
// const sum = function(num1, num2){
//   return num1 + num2
// }

// //arrow function
// const sum = (num1, num2) => {
//   return num1 + num2
// }

// const sum = (num1, num2) => num1 + num2

// const sum = num1 => num1 + num1

// console.log(sum(1, 2))

//statement vs Expression

//statement means command
//Expression means value

//can be written as right side of variable (expression)
//can't be written as right side of variable (statement)

//first class function
//criteria
//can be written right side of a variable
//can be passed as arguments, receive as a parameter
//can be return from function

//Higher order Function function, callback
//A higher order function is a function that takes a function as an argument, or returns a function

// function higherOrderFunc(fn){
//    fn(1, 2)
// }

// const callbackFn = function (num1, num2) {
//   console.log(num1 + num2)
// }

// higherOrderFunc(callbackFn)

//Higher order function
// function sum(num1){
//   return (num2) => {
//     return num1 + num2
//   }
// }

// const innerFn = sum(3)
// console.log(innerFn(4))
// console.log(sum(3)(4))

//Javascript "this"

//this outside of function(window)
//this inside of  a function
  //depends on how you call the function
  //if it is called in a plain way (window) strict mode(undefined)
  // if you call as object reference it will indicate the object
  //If you call with constructor function "this" indicates empty  object and can be fulfilled and returned

//outside of function
// console.log(this)

// //inside of function
// function thisFn() {
//   console.log(this)
// }

// thisFn()

//attaching with window object
// var firstName = 'Hono'
// var lastName = 'Mono'

const profile = {
  firstName: 'samim',
  lastName: 'Hasan',
  fullName() {
    const $this = this
    function innerFunc() {
      console.log('innerFunc', $this)
    }
    innerFunc() //plain way

    // innerFunc.call(profile) //plain way
    return this.firstName + ' ' + this.lastName
  }
}

console.log(profile.fullName)

const fullNameRef = profile.fullName
console.log(fullNameRef.call(profile))

// console.log(profile.fullName())

// function fullName(age1, age2) {
//   return this.firstName + this.lastName + age1 + age2
// }

// const obj = { firstName: 'samim', lastName: 'Hasan' }

// const result = fullName.call(obj, 27)
// const result = fullName.apply(obj, [27, 30])

//like call (but do not call the function)

//for call and apply
// console.log(result)

// const result = fullName.bind(obj, 30, 35)
// //for bind
// console.log(result())

//constructor function

// function Profile() {
//   // console.log(this)
//   this.firstName = 'Honu'
//   this.lastName = 'Monu'
//   this.fullName = function () {
//     return this.firstName + this.lastName
//   }
// }

// const profile = new Profile()
// console.log(profile)
// console.log(profile.fullName())

let callArray = [0, null, '', undefined, 2, 3]
function truthyValue(findtruthy) {
  let arr = []
  if (Array.isArray(findtruthy)) {
    for (let elm of findtruthy) {
      if (elm) {
        arr.push(elm)
      }
    }
  } else {
    console.log('Not array')
  }
  return arr
}

const checkIngArray = truthyValue(callArray)
console.log(checkIngArray)