What is the difference in these 2 javascript expressions?

Question

I am refactoring some javascript code and came across this expression:

false === options.onSubmit.call(this)

What would be the purpose to put the false first? Is there a difference between that expression and this expression?

options.onSubmit.call(this) === false

http://en.wikipedia.org/wiki/Yoda_conditions – VisioN Aug 30 '14 at 15:42 — VisioN, Aug 30 '14 at 15:42

Mritunjay · Answer 1 · 2014-08-30T16:45:29.480

2

What I think the best benefit of that is you can't accidentally do assignment instead of compare. It comes in place basically with == check.

When you want to compare two values like bellow

someVariable === false

OR

someVariable == false

could be accidently

someVariable = false

But

false = someVariable

Will cause a error ReferenceError: Invalid left-hand side in assignment. So you will get rid of that mistake.

edited Aug 30 '14 at 16:45

answered Aug 30 '14 at 15:46

Mritunjay

Besides this approach is more readable than the opposite. – VisioN Aug 30 '14 at 15:48
@VisioN yes I agree with you, but every thing has it's own pros & cons. – Mritunjay Aug 30 '14 at 15:49
They'll both cause the same error given that example. – cookie monster Aug 30 '14 at 16:17
@cookiemonster could be just talking about why this way is used. – Mritunjay Aug 30 '14 at 16:20
Sure. Point is that there's no difference the way this is used in your example. It could be confusing to people since it doesn't show a real world example where it would actually make a difference. – cookie monster Aug 30 '14 at 16:42

1 Answers1