Lazy Count the number of results

Is there any way of counting the number of filtered objects from a realm js query without using JS’s .length property?

Code Sample

I am doing this:

const maleCount = realm.objects('Person').filtered('gender == "male"').length;

And I wanted to know if there is a faster way of doing so, some Realm method as to not throw away the laziness Realm provides.

[kneth]

.length is implemented using functions in Realm Core (our storage/query engine), and it is a fairly cheap to compute.

If you have

let males = realm.objects('Person').filtered('gender == "male"');
let maleCount1 = males.length;
// do a lot but no changes to Person
let maleCount2 = males.length;

the second invocation of .length with not rerun the query.

The short answer is that we don’t expose any other method to compute the length of a result set.

[cristianoccazinsp]

Since realm pretty much locks the entire app while it is running a query (not async), I would say the time budget is not too high. This is an operation intended to run shortly after an app start to do some cleanup and gather statistics. I guess I will need to test a real use-case and time it. But constant time sounds decent for this, as we are talking of about a few thousand items.