Sort ruby array in descending order with nil values and multiple arguments

Question

First, I have found posts to sort values with possibles nil values, other posts to sort decending, but I didnet find the solution with both.

Here is where I am:

@records = @records.to_a.sort_by do |r| [-r.optimized_all_count, [r.year ? 1 : 0, r.year]] end

This works very well, but I want the "year" comparator to be descending. I tested this:

-[r.year ? 1 : 0, r.year]

but the sign "-" won't work with nil values. I also tried a.reverse...

How do obtain the year argument descending (and keeping -r.optimized_all_count as first sorting argument), ideally:

2020, 2018, 2017...nil, nil, nil.

Thanks

@records.to_a – is there by chance a database query involved? — Stefan
– Stefan, Commented Jan 11, 2021 at 15:21
'to_a' is not required, and yes, it was an AR database query. — alex.bour
– alex.bour, Commented Jan 11, 2021 at 16:00

Daniel Sindrestean · Accepted Answer · 2021-01-11 15:28:02Z

1

Try this:

@records = @records.to_a.sort_by do |r| [-r.optimized_all_count, [r.year ? 0 : 1, r.year ? -r.year : nil]] end

answered Jan 11, 2021 at 15:28

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Comments

Cary Swoveland · Accepted Answer · 2021-01-11 16:21:38Z

1

@records.to_a.sort_by { |r| [-r.optimized_all_count, -(r.year || -Float::INFINITY)] }

It's not clear if .to_a is required.

answered Jan 11, 2021 at 16:21

Cary Swoveland

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'to_a' is not required in fact. Your solution is also working Cary, and shorter. Thanks.