Update api.md

[buom]

correct the default filter

[larsga]

Thank you for fixing the wrong method call in the documentation. That's much appreciated! 👍

Unfortunately, the other suggested change is wrong (see detail comment). If you can remove that I'll merge the PR.

[larsga]

This addition is not correct. As you can see here it really is null, {}, and [] that are the omitted values.

The suggested change would, for example, filter out true, and 5, and so on.

[buom]

@larsga Here we have two different implementations:

1. Default implementation: NodeUtils.isValue(value); - here
2. Custom implementation: NodeUtils.isTrue(jslt.apply(value)); - here

NodeUtils.isValue(value) != NodeUtils.isTrue(value)

[larsga]

Yes, that's true, but the example expression says how to reproduce the default behaviour, which is your number 1.

[sorawee]

I think the right fix would be to negate the expression, right?

. != null and . != {} and . != []

When the filter returns true, it means we want to keep the value. So here, we want to keep all values that are (1) not null AND (2) not {} AND (3) not [].