Code sample -class(8)

//simple(for loop, while loop, do while)
//specific to array(simple loop + extra way(for of, forEach, map, reduce, find, filter, findIndex, every, some))
// array helper method
//specific object(for in)

//foreach
// const nums = [1, 2, 3, 4]
// let total = 0
// nums.forEach(num => total += num)

// console.log(total)

//map
// works on array
// manipulate every element of array
//return an array
// don't modify the existing array

// const nums = [1, 2, 3, 4]

// const result = nums.map(num => {
//  return num * 3
// })
// const numbers = [50, 30, 90, 25]

// const result = numbers.map(num => num < 33 ? 'Fail': 'pass'
// )

// console.log(result)
// console.log(nums)

//find
// works on array
// find an element(first occurrence)
//return a value
// don't modify the existing array

// const nums = [1, 2, 3, 4, 5, 6]

// const result = nums.find(num => num > 4)
// console.log(result)

//filters
// works on array
// find elements based on condition(first occurrence)
//return an array
// don't modify the existing array

// const nums = [1, 2, 3, 4, 5, 6]

// const result = nums.filter(num => num > 4)
// console.log(result)

//some
// works on array
// // return true/false if one element is true based on condition
//return an single value(true/false)
// don't modify the existing array

// const nums = [1, 2, 3, 4, 5, 6]

// const result = nums.some(num => num > 4)
// console.log(result)

//every
// works on array
// return index if every element is true based on condition
//return an single value(true/false)
// don't modify the existing array

// const nums = [1, 2, 3, 4, 5, 6]

// const result = nums.every(num => num >= 1)
// console.log(result)

//findIndex
// works on array
// return index number of first occurrence based on condition
//return an single value
// don't modify the existing array

// const nums = [1, 2, 3, 4, 5, 6]

// const result = nums.findIndex(num => num === 7)
// console.log(result)

//reduce

// const nums = [1, 2, 3, 4, 5, 6]
//1) prev - 1
//curr- 2
//2) prev-what you return
//curr -3
//3)prev-what you return
//curr -4

// const result = nums.reduce((previousValue, currentValue) => {
//   // console.log(previousValue)
//   // console.log(currentValue)
//   return previousValue + currentValue
//   // return 'Hello'
// })

// const result = nums.reduce((previousValue, currentValue) => {
//   // console.log(previousValue)
//   // console.log(currentValue)
//   return previousValue + currentValue
//   // return 'Hello'
// }, 0)

// console.log(result)

//Hoisting (Lifting up)
// var a = 1
// console.log(a)
// var a = 1
// console.log(a)

// console.log(sayHi)
// function sayHi(){
//   return 'Hi'
// }
// const sayHi = () => {
//   return 'Hi'
// }

// console.log(sayHi())

//preparation stage

//1)Declaration
//2) function block in memory
//execution stage
//calling, assignment

//preparation stage
 var a

 function sayHi(){
  return 'Hi'
}

//execution phase
console.log(a)
a = 1
console.log(a)
console.log(sayHi())
console.log(sayHi())

//temporal dead zone(Let , Const)