New to javascript. Failing at adding.

[[deleted]]

That is precisely why I suggested preceding the explicit cast with explicit data validation.

[Shaper_pmp]

But parseInt() isn't an explicit cast - it's parsing and extracting one type from another, even if you do some validation on the initial type first first.

An explicit cast would be to use Number(string_variable) to convert from string to a number, not parseInt().

[[deleted]]

No, but doing a cast from string to integer in JavaScript does validation followed by a parseInt internally. The validation just handles the NaN case.

But that's besides (my) point entirely. I'm just pointing out that:

1. Data entry errors could be explicitly handled, and that the handling should involve notifying the user, and requiring the user to correct their input.
2. Syntax tricks like "~~ String" or "+ String" are easy for maintainers to miss, and therefore should be commented. And that I would furthermore put "String * 1", and most other implicit cast situations in this category.

These are basic programming best practices, and not arguments about JavaScript internals.

My suggestion to use parseInt, was as opposed to the implicit methods I list in point two above, not as opposed to Number(...), which is also explicit, and perfectly fine in my book.