Swift - How to sort and array by optional property

Question

Say I have a Cat class with this property:

var order: Int?

I have an array of these classes that I need to order by this property:

let sortedCats = cats.sorted(by: { $0.order > $1.order })

I get this error:

"Binary operator '>' cannot be applied to two 'Int?' operands"

What's the proper way to do this?

It depends on how you want to treat the orderless cats (those whose order == nil). Should an orderless cat compare less than or greater than any ordered cat? — Jens
– Jens, Commented Aug 17, 2020 at 21:21

EmilioPelaez · Accepted Answer · 2020-08-17 21:10:52Z

1

Use a default value of .min which is the smallest number you can have on an Int

let sortedCats = cats.sorted(by: { $0.order ?? .min > $1.order ?? .min })

answered Aug 17, 2020 at 21:10

EmilioPelaez

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