Writing Special Sort Functions

Some Perl functions require that you write your own function to alter the default behavior of the Perl function. The best example of this is the sort function. Whenever data is sorted, there are two phases to the algorithm: the comparison phase, to see if elements are out of order, and the exchange phase, to put them in order. The default comparison for the sort is to compare items lexicographically. This is why the following program produces the output that is displayed. See the folder DefSort.

% type defsort.pl
#
#       defsort.pl
#
@numbers = (1, 15, 100, 250, 2, 200, 15, 25);
print join("\n", sort(@numbers));
% perl defsort.pl
1
100
15
15
2
200
25
250
%

If you want to sort these values numerically, you need to ...

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