class-2 -Introduction to Javascript

Let's Talk to Computer
// Everything is data....
// I am samim, I am 30, I am a programmer

//Checking data type
// I
// am
// samim
// 30
// a
// programmer


// Declaring variable
//  *Rules- camelCasing, pascalCase
//  let, var, const
// Javascript Data type
//  primitive
//   - string
//   - number
//   - boolean(true, false)
//   - undefined
//   - null
//   - Symbol
//   - Bigint


//  Object/complex data type
//   - array
//   - object
//   - function


//labelling data(variable)/container
//naming variable
// Variable names cannot contain spaces.
// Variable names must begin with a letter, an underscore (_) or a dollar sign ($).
// Variable names can only contain letters, numbers, underscores, or dollar signs.
// Variable names are case-sensitive.
// special (reserved keyword array not allowed)

//var,let,const
// const firstName = 'samim' //string (anything  wrapped in single or double quote
// const age = 3 //number
// var profession = 'programmer'//(Don't use)

//always declare with const

//data type
//primitive
const firstName = 'samim' //string
const age = 3 //number
const isDeveloper = true //(boolean)
const isMachineEngineer = undefined //(Never use)
const isDesigner = null
// const randValue = Symbol() //generate unique value
// const bigNum = 1212313n //bigint

//complex/object data type
//array
// const person = ['samim', 30, true, null]
// console.log(person[0], person[1])

const personObj = {
  name: {
      first: 'samim',
      last: 'Hasan'
  },
  age: [30, 40, 20],
  isDeveloper: true,
  isDesigner: null,
}

//object
personObj.name.first = 'anis'
personObj.location = 'Dhaka'
console.log(personObj)
//accessing property /key
console.log(personObj.name.first)
console.log(personObj['firstName'])
console.log(personObj.age[2])
console.log(personObj.isDeveloper)


//function
//will be discussed later