A Comprehensively Short Guide to let, var and this
Back in September, I wrote this story on var
, let
and the keyword this
However, some people still found it hard to distinguish between the difference — or rather, they wanted something that was more visually accessible. So I decided to change the format a little for today’s piece.
Here is your comprehensively short guide/notes version to let
, var
and this
var, let and this recap:
- JavaScript is a lexical language — this means inheritance flow inwards
- if a variable is declared at the root level, it becomes a global variable and accessible by everything
var
is scoped to the nearest function block, meaning the closest{ }
pair that’s attached to a function.let
is scoped to the nearest closing block, meaning the closest{ }
pair, regardless of what it is.this
lets you access variables that are outside the closing block and function scopes. Depending on what you used (i.e.let
orvar
), it can change the way results are returned.
And that’s basically var
, let
and this
in nutshell.