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Software developers are always working with arrays. In
Perl, that means that you're working with (a) normal arrays
or (b) hashes (called 'associative arrays' before Perl 5.x).
When it comes to 'normal arrays', we're often asked the
question "How do I do <fill-in-the-blank> for each
element in an array"? Here's a simple technique we
often use:
#!/usr/bin/perl -w
@homeRunHitters = ('McGwire', 'Sosa', 'Maris', 'Ruth');
foreach (@homeRunHitters) {
print "$_ hit a lot of home runs in one year\n";
}
In this example, homeRunHitters is
a simple array (i.e., it's just an array indexed
by number; hashes
are arrays indexed by strings).
Here, we use the foreach
statement to cycle through the elements in the array.
The special variable $_
holds the value of the element being processed
during each loop in the foreach
statement.
Output from this program looks like this:
McGwire hit a lot of home runs in one year
Sosa hit a lot of home runs in one year
Maris hit a lot of home runs in one year
Ruth hit a lot of home runs in one year
If you're interested in using this technique when
tackling your arrays, all you have
is put your logic inside of the foreach
loop.
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