Re: How do I check to see if a value in a hash is equal to something?

One way would be by inverting the hash and looking things up by value, as described in perlman:perlfaq4 (see How do I look up a hash element by value?).

Another way, of you are only interested in knowing if the value is in the hash, without knowing the key, could be:

$is_in_hash=grep /^Superman$/,values(%hash);
[download]

This is not particularly space efficient if the hash is large. See also the second solution suggested in the FAQ mentioned above.

--ZZamboni

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RE: Answer: How do I check to see if a value in a hash is equal to something? by merlyn (Sage) on May 23, 2000 at 19:47 UTC
It has been said: Another way, of you are only interested in knowing if the value is in the hash, without knowing the key, could be: `$is_in_hash=grep /^Superman$/,values(%hash);` [download] This is not particularly space efficient if the hash is large. See also the second solution suggested in the FAQ mentioned above. Rather than using a regular expression, just use an ordinary expression: `$is_in_hash = 0 < grep $_ eq "Superman", values %hash;` [download] -- Randal L. Schwartz, Perl hacker	[reply] [d/l] [select]

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RE: Answer: How do I check to see if a value in a hash is equal to something?
by merlyn (Sage) on May 23, 2000 at 19:47 UTC

Another way, of you are only interested in knowing if the value is in the hash, without knowing the key, could be:
$is_in_hash=grep /^Superman$/,values(%hash);
[download]
This is not particularly space efficient if the hash is large. See also the second solution suggested in the FAQ mentioned above.

$is_in_hash = 0 < grep $_ eq "Superman", values %hash;
[download]

-- Randal L. Schwartz, Perl hacker

[reply]
[d/l]
[select]