class-1(Essential JavaScript for react)

//var,  const let
//function declaration, arrow function and single line return
//template string/literal
//conditional and logical AND(&&)
//Array helper method(map, filter, find)
// Destructuring, rest, spread
// promise, async await
// class

//Let, var, const
// var a = 10 //Don't use(to avoid some unexpected  error, bug)

// const b = 20
// let c = 30

// // b = 40 //error
// c = 50

// console.log(c)

//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 multiply = (num) => num * 20

// console.log(multiply(10))

// const firstName = 'samim'
// const lastName = 'Hasan'

// const fullName = firstName + ' ' + lastName
//javascript expression can be written inside in curly braces
//statement - command (;) expression-value
// const fullName = `My First Name is "${firstName.toUpperCase()}" and last name is "${lastName.toUpperCase()}".`

// console.log(fullName)

//conditional

// const age = 20

// if (age >= 18) {
//   console.log('You can vote')
// } else {
//   console.log("You can't vote")
// }

//ternary
// condition? true : false

// const result = age >= 18 ? 'You can vote' : 'You can\'t vote'

//logical and operator(&&)
// const result = age >= 18 && 'You can vote'

// const result = age >= 18 || 'You can vote'

// console.log(result)

// function double(nums) {
//   const dbl = []
//imperative coding
//   for (let i = 0; i < nums.length; i++) {
//     dbl.push(nums[i] * 2)
//   }
//declarative
//   for (let num of nums) {
//     dbl.push(num * 2)
//   }
//   return dbl
//declarative
//   const result = nums.map((num) => num * 2)
//   return result
// }

// const nums = [1, 2, 3, 4]
// console.log(double(nums))

//[2, 4, 6, 8]

//find
// function findElm(recArr) {
//   return recArr.find((elm) => elm > 2)
// }
// const nums = [1, 2, 3, 4]
// console.log(findElm(nums))

//filter

// function filterElms(recArr) {
//     return recArr.filter((elm) => elm > 2)
//   }
//   const nums = [1, 2, 3, 4]
//   console.log(filterElms(nums))

//destructuring,
// const person = {
//   firstName: 'samim',
//   lastName: 'Hasan',
//   age: 30,
// }

// const { firstName, age } = person

// console.log(firstName)
// console.log(age)

// rest operator
// const { firstName, ...restValues } = person
// console.log(firstName)
// console.log(restValues)

// // spread operator
// const newPersonObj = {
//     ...person,
//     profession: 'Programmer'
// }

// console.log(newPersonObj)

// //array destrucring, rest, spread operator
// const arr = [1, 2, 3, 4]
// const [num1, num2, ...restArr] = arr
// console.log(num1, num2)
// console.log(restArr)
// const newArr = [...arr, 5]
// console.log(newArr)
// console.log(arr)

// function viewPerson({ firstName, lastName, age }) {
//   return firstName, lastName, age
// }

// const person = {
//   firstName: 'samim',
//   lastName: 'Hasan',
//   age: 30,
// }

// console.log(viewPerson(person))

//callback

//promise
// fetch('https://jsonplaceholder.typicode.com/todos/1')
//   .then((response) => response.json())
//   .then((json) => console.log(json))
//   .catch(err => console.log(err))

//async await
// async function run(){
//     try{
//         const res = await fetch('https://jsonplaceholder.typicode.com/todos/1')
//         const data = await res.json()
//         console.log(data)
//     }catch(err){
//         console.log(err)
//     }

// }

// run()

class Person {
  //filed/property
  // name = 'samim'
  // age = 30
  constructor(mName, mAge) {
    console.log(mName, mAge)
    this.name = mName
    this.age = mAge
  }
  //method
  showInfo() {
    return this.name + '-' + this.age
  }
}

// const person = new Person('khalil', 35)
// console.log(person)
// console.log(person.name)
// console.log(person.age)
// console.log(person.showInfo())
//subclass(child class) and inheritance
class Student extends Person {
  constructor(name, age, course) {
    super(name, age)
    this.course = course
  }

  showCoursesInfo() {
    return super.showInfo() + ' ' + this.course
  }
}

const student = new Student('anis', 25, 'React Student')
console.log(student)
console.log(student.showCoursesInfo())
console.log(student)