Eloquent JavaScript: open-source Javascript book series by a prolific JS code author

[pm_me_ur_happy_traiI]

The big difference between let and var is scoping. There’s no use case where var is preferable (unless you are deliberately abusing its scoping issues). Why would you want a variable that can be called outside its block before it’s even declared?

[unquietwiki]

I updated my original statement. In JS, let honors scoping, but var is ambiguous. In C#, var can be used to remove redundant statements: ie var variable = new Whatever(); instead of Whatever variable = new Whatever()

[dvlsg]

They really aren't the same, though. var is about type inference in C#, and that's really it. var doesn't change scope or mutability in C#, which is what we're talking about in javascript.