Class 2

//today's cover topic
    //data type
    //work of console log
    //truth and false value
    //work of variable and what is variable



//use of console.log
// console.log('dsfsdfasdfksad;fjsd') //print the data




//data type

//what is variable
//var let  const
// var name = 'shopnil'
//in c++
// string name = "shopnil"
// int x = 5
//float x = 5.5
//bool x =true
// console.log(name)
// console.log(name)
// console.log(name)
// console.log(name)

// console.log("rohinga")
// console.log("rohinga")
//c++
//int , double, float, bool, string
//15 , 15/15.5, 15.5 , true/false, "a-z"

//array, function
//js
//data type // 2 type
//1. primitive
//2.Object

//Primitive //3 type
//1.number 1 , -1, 15.35
//2. boolean
//3.string

//Number
// [0-9], (-ve) , 25.5

//boolean
//true false

//string
//[a-z][A-Z] "" or 'true false'

//primitive data type end



//Object // 3 types
//1.array
//2.function
//3.object

//other
//NaN, undefined, null

//NaN
// var data = Number("lakjflsda")
// console.log(data);

//undefined
// var x
// var y = 5
// console.log(x) //error
// console.log(y)

//truthy value and falsy value
//1.falsy data  (NaN, undefined, null , 0, "", false)
//Boolean()

var res
var a = Boolean(res)
console.log(res); //undefined
console.log(a); //false