Can anyone tell when to use keyword var and keyword let?

Answer 1

You should use "let" when you sure that containing value wouldn't change. It is a constant (like number Pi or else). "let" help us use system memory better

Answer 2

var is a variable , which changes
but let is a constant , which doesn't change

Answer 3

var declares a variable whose contents can be changed whereas let declares a constant that connot be changed (i.e. let myFirstName = Scott vs var myFavoriteColorToday = Blue). Its unlikely that I'll change my first name but it's quite possible that I might choose a new favorite color.

Answer 4

let will be used when you are sure there is no change in value like universal truth or mathematical equations for example π=3.14, it will never change.

var will be used for normal variables

Answer 5

simply, (let) is used when you define a constant wich eventually will hold a fixed value. and var is used when you define a variable that will change its value

Answer 6

Basically, things like someone's age is "var", someone's gender is a "let"

Answer 7

let π = 3.14 // It is a constant and we should use let keyword to avoid changing it by accident or sonething like that.

Answer 8

If you use let, the value can't be changed
If you use var, it can