What is var? Should I use it or not?

Question

Is it essential to add var to js code every time, or not?

I'm asking this question, because my js code is working well, even if I don't add var. And both codes with and without var are showing same results

If u understand it, plz explain it to me with examples

Answer 1

Good observation.

Small codes work without var keyword.

Without var keyword, variables are added to window as a property, and are all in the global scope.

With var keyword, variables are functional scoped.

With let keyword, variables are block scoped.

When your code grows, you should use keywords to keep variables in their local scope.

Answer 2

丹ⓨㄩک廾 You are welcome ^^

So in JavaScript, we can assign value to variables without the var or let keyword. But that makes the variable global-scoped, even if it initiated in a function, which'll lead to name contamination, and hard-to-debug bugs.

Here is a styling guide for JavaScript, by the famous IT corporation AirBnB:
https://www.sololearn.com/post/664911/?ref=app

https://code.sololearn.com/WKKkpq0efxai/?ref=app

Answer 3

Apparently you didn't catch the point the asker is asking. 丹ⓨㄩک廾 Sagar Maurya

Please refer to

line 54 to line 74

of the following code :

https://code.sololearn.com/WwhKQUoMbXHH/?ref=app

And refer to console result.

https://www.sololearn.com/post/57512/?ref=app

https://code.sololearn.com/Wyr76080kKxS/?ref=app

Answer 4

Yes it necessary without this you can't write ur code properly
Check here in easy understanding way
https://www.studytonight.com/

Answer 5

O I see I got it Gordon sir. Thanks for correcting me. 😌