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How do I shuffle an array?

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Contributed by vroom on Jan 08, 2000 at 08:19 UTC
Q&A  > arrays

Answer: How do I shuffle an array?
contributed by hossman

The List::Util module provides a shuffle function which implements the Fisher-Yates shuffle.

use List::Util qw(shuffle); my @data = (0..51); my @cards = shuffle @data;
Answer: How do I shuffle an array?
contributed by vroom

The Fisher-Yates shuffle is easy to code up:

# randomly permutate @array in place sub fisher_yates_shuffle { my $array = shift; my $i = @$array; while ( --$i ) { my $j = int rand( $i+1 ); @$array[$i,$j] = @$array[$j,$i]; } } fisher_yates_shuffle( \@array ); # permutes @array in place

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