Using map but not capturing the returned values: 

map { something( $_ ) } @somelist;

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In recent versions that's been optimized (basically the return values are silently discarded rather than a temporary list built and then discarded later) so it's not as blecherous performance wise.

However it really buys you nothing to use it instead of a for loop here, because you've now muddled the conceptual waters (Was it at one point using the returned values and changed? Did they plan on possibly using them at some point?) and makes the code harder to understand (rather than the important thing (what's being iterated over) being up front, you've got to read past the details (what's being done for each item) to find out). It's along the lines of using passive or active voice in a sentence ("The cow jumped over the moon." vs "The moon was jumped over by the cow"); using the wrong one can shift what the reader takes as the emphasis to the wrong part.

The cake is a lie.
The cake is a lie.
The cake is a lie.

In reply to Re^4: map versus for by Fletch
in thread map versus for by dHarry

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