in reply to Re^2: sorting an array with decimal points
in thread sorting an array with decimal points

Hi Laurent_R,

it might actually work thanks to the coercion of version numbers into decimal numbers imposed by the <=> operator

Yes, the spaceship operator will always compare in numeric context - and I was quite confident that if the only problem with levW's 
sort  { substr($a, 6,2) <=> substr($b, 6,2)} @array

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was that it failed to sort in the correct order, then 
sort  { substr($a, 6) <=> substr($b, 6)} @array

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would fix that.

But levW seemed to think that there was a problem re the decimal point (which I don't see), and I was a little unsure about other aspects of the requirements, so I shied away from investing much time into my reponse.

Cheers,
Rob

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Re^4: sorting an array with decimal points
by Laurent_R (Canon) on Jan 15, 2018 at 23:16 UTC
    Yes, the reason I answered your post was that I thought other monks might make the same mistake I initially made: that's why I thought it was worth showing that your solution worked for the sample data shown because of numeric coercion, and also to show the test.

    This being said, and as pointed out by AnomalousMonk in Re: sorting an array with decimal points, if the OP's data is really representing version numbers (and I think that's what they are) and not decimals, then your solution would fail on, for example, 5.2, 5.14, 5.16, 5.20, because it would sort 5.2 after 5.14 and 5.16 (which would be wrong for version numbers).

    But, of course, my assumptions that they are version numbers may also be wrong. Only levW can tell us what they really are.

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