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JavaScript

Posted by Kent Hefley
Kent Hefley
11,217 Points

Why "Let", "Const" and not "Var"

My question is based in the fact that I don't quite understand their differences. The intro to Javascript courses with Dave McFarland use "var" in each example. Why is "var" not used in this project course

1 Answer

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Kent,

let and const are newer keywords that you can use to declare variables in javascript. You didn't specify which course you're on but I would guess that you're on a newer course as opposed to the older courses you mentioned which would be using the var keyword.

One of the benefits of let and const is that it gives you block level scope for variables. So in other words, a variable declared with those keywords inside a loop, would only exist inside the loop.

With the var keyword, variables either exist for an entire function, if declared inside a function, or they exist in global scope if not declared within any function.

The following workshop explains these newer keywords: https://teamtreehouse.com/library/defining-variables-with-let-and-const

Kent Hefley
Kent Hefley
11,217 Points

Thank you Jason. You are right. I am taking the Javascript and the Dom course. I will watch the workshop you suggested.