Building a Module
To understand how a module is put together, let's walk through a simple example: a small statistics library. This will re-use functions from the end of Hour 8, abbreviated for space. The sample module, which we're going to call TYPStats, is shown in Listing 17.1.
Listing 17.1. Statistics Module
1: #!/usr/bin/perl -w
2: use strict;
3: package TYPStats;
4:
5: sub mean {
6: my(@data) = @_;
7: my $sum;
8: $sum += $_ foreach(@data);
9: return @data ? ($sum / @data) : 0;
10: }
11: sub median {
12: my(@data)=sort { $a <=> $b} @_;
13: if (scalar(@data) % 2) {
14: return($data[@data / 2]);
15: }
16: return(mean($data[@data / 2],
17: $data[@data / 2 - 1]));
18: }
19: 1;
|
This should be saved into a file called TYPStats.pm in the same ...
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