JSONata vs JavaScript

General
1

Is there a good reason why the behavior of JSONata $number(value) is different than Javascript Number(value)?

e.g. $number(".5") will fail to cast as a number where as Number(".5") will cast to the numeric value of 0.5 as expected.

I continually find myself using Function nodes (when I don't really want to) because I run into issues like the above when using a Change node and JSONata.

2

You might need to ask that question on the JSONata site rather than here?

The other question I'd ask is why you prefer JSONata over JavaScript? JS is a lot more efficient in general and really, the only benefit of JSONata is when it can do object reshaping easily for you that would be complex in JavaScript.

3

It's not that I prefer JSONata over JS... it's just the paradigm of Node-RED being a 'low code' flow based, programming tool I was trying to minimize my usage of the Function node and rely on various functional type nodes (such as the Change node)... but I continually run into situations like this where I need to "sanitize" the incoming data and I end up reverting to Function nodes with bits of JS.

I just thought perhaps I was missing something or didn't understand how to use some of the built-in nodes effectively?

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4

JSONata is pretty strict. TBH ".5" is not something I would enter in any programming language, as it's easy not to see the decimal point when debugging. Just my opinion.

$number("0.5")

works.

5

:wink: nope.

I think you will find that most people who know JavaScript but who use Node-RED use function nodes a lot because we can create a small nugget of code that itself does a lot in a few lines. But we use Node-RED because it can do a LOT with no code and it gives us an operating environment that is consistent and robust.

6

JSONata is designed to work with strict JSON valid types. ".5" is not a valid representation of a number in JSON, so JSONata doesn't handle it.

A case could certainly be made for it to be slightly more relaxed... but that's something to take up with the JSONata project.

7

Thanks for the explanation Nick.

8

I don't disagree... but in this case I'm dealing with data being pulled from a database I have no control over. And when you are dealing with multi-purpose text fields, "numbers" can be stored any which way the user inputs them... thus the need to "sanitize" the data as it is pulled in.

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9

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