Discussion on: Where do I start? Part 3: JavaScript

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Replies for: Kevin, Great post, but why do you feel using "var" is a non-starter? Since, I use it quite often. Is this a bad coding practice?

Muhammad Arslan Aslam • Mar 11 '19

According to some JavaScript experts, yes. You shouldn't use var. Use const &/|| let.

The reason for that,

var isn't block-scoped
No warnings/errors given if you declare the same variable twice using var
Some modern linters give warnings stating var is a bad coding practice

Should You Truly Never Use var?

John Wolfe

#javascript#react#ecmascript6#variables

E.Mabry • Mar 11 '19

Thanks for that explanation. I never looked at it that way Muhammad. After reading the article I understand. I just have never had any problem with it. I do see the benefit with block-scoped and I do recognize the errors it gives using some linters. I will give it a try.

Muhammad Arslan Aslam • Mar 11 '19

Glad I could help <3

Zac Heisey • Mar 12 '19 • Edited

I think Muhammad brings up some solid points here as to why you wouldn't want to use var. However, I don't agree with the author's notion that var should never be used. In fact, I'd argue that using var in the early stages of learning JavaScript will make the concept of declaring, changing, and working with variables easier to understand.

Chris Ferdinandi, a vanilla JavaScipt expert, has a nice explanation on why he doesn't use let or const in his projects: gomakethings.com/why-i-dont-use-le...

His reasoning: let and const aren't as backwards compatible as var, they can't be polyfilled, and trying to determing which type to use adds unnecessary cognitive overhead (especially for beginners).

Muhammad Arslan Aslam • Mar 12 '19

I totally agree with you. For a beginner, using var can be a good thing to understand working with variables.