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How do I Loop over multiple arrays simultaneously ?

( #825340=categorized question: print w/ replies, xml ) Need Help??
Contributed by Fox on Feb 25, 2010 at 16:54 UTC
Q&A  > arrays


Description:

Taken from RosettaCode...

How do I loop over multiple arrays and print the ith element of each?

For example, looping over the arrays (a,b,c), (A,B,C) and (1,2,3) to produce the output:

aA1 bB2 cC3

Answer: How do I Loop over multiple arrays simultaneously ?
contributed by Fox

And the answer from RosettaCode:

sub zip (&@) { my $code = shift; my $min; $min = $min && $#$_ > $min ? $min : $#$_ for @_; for my $i ( 0 .. $min ) { $code->( map $_->[$i] , @_ ); } } my @a1 = qw( a b c ); my @a2 = qw( A B C ); my @a3 = qw( 1 2 3 ); zip { print @_,"\n" } \( @a1, @a2, @a3 );

This implementation will stop producing items when the shortest array ends.

Answer: How do I Loop over multiple arrays simultaneously ?
contributed by jdporter

use List::MoreUtils::each_array:

use List::MoreUtils qw( each_array ); my @a = qw( a b c ); my @b = qw( A B C ); my @c = qw( 1 2 3 ); my $ea = each_array( @a, @b, @c ); while ( my( $a, $b, $c ) = $ea->() ) { print $a, $b, $c; }
:-)
Answer: How do I Loop over multiple arrays simultaneously?
contributed by gaurav.trikha

Well, assuming that it's certain that the arrays are all the same length, just translate the statement of the problem into Perl: have an index going the length of one of them, and then use it in all of them:

my @a = qw( a b c ); my @b = qw( A B C ); my @c = qw( 1 2 3 ); for my $i ( 0 .. $#a ) { print $a[$i], $b[$i], $c[$i]; }

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