Javascript variables and data types

Variable: containers that hold values
var x = 10 ;
var x is variable
10 is value
variable is loosely typed
Js data types are :
1-undefined
2-number
3-string
4-boolean
5-null
Any variable has undefined data type as initial value until you assign value to it

You can know the type of the variable by using typeof
console.log(typeof x)