initial js
close alert
console

Signed-off-by: sudebkumar <sudeb.phy137@gmail.com>
see result
defining variable
number data type
Signed-off-by: sudebkumar <sudeb.phy137@gmail.com>
error finding
properties of window
alert using window
using in operator
add using js
itroducing NaN
using number function
using parseInt
undefined number/true or false
defined and calling function
functioncall
argument
self executing function
sum as a global variable without var key word