Re^2: How to test for empty hash?

update: it's wrong, only read further to learn from mistakes ;-)

> to portably get the number of keys in a hash, use keys in scalar context; scalar(%hash) is not backwards compatible

nitpick for the sake of fun, b/c of the magic of the string_to_number conversion using it as a number will portably work.

(tho I'd also prefer using keys here :)

  DB<1> p $]
5.024001

  DB<2> %h=(a=>0)

  DB<3> p scalar %h
1/8

  DB<4> p 0+ %h
1

  DB<5>
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery}

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Re^3: How to test for empty hash? by haukex (Archbishop) on Aug 06, 2021 at 11:14 UTC
nitpick for the sake of fun, b/c of the magic of the string_to_number conversion using it as a number will portably work. Sorry, no, it doesn't: `$ perlbrew exec perl -e '%h="a".."z";warn"$] ".keys%h," ".%h," ",0+%h, +"\n"' >/dev/null 5.034000 13 13 13 5.032001 13 13 13 5.030003 13 13 13 5.028003 13 13 13 5.026003 13 13 13 5.024004 13 8/16 8 5.022004 13 10/16 10 5.020003 13 7/16 7 5.018004 13 11/16 11 5.016003 13 9/16 9 5.014004 13 9/16 9 5.012005 13 9/16 9 5.010001 13 9/16 9 5.010000 13 9/16 9 5.008009 13 9/16 9 5.008001 13 12/16 12 5.006002 13 4/8 4` [download] Minor edits to shorten output.	[reply] [d/l]
Re^4: How to test for empty hash? by LanX (Saint) on Aug 06, 2021 at 12:37 UTC
damn you're right... ... of course `#buckets <= #keys` because of collisions. Thanks for the correction! :) Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l]