I cannot resist. You can also use a closure, every time you call it you get 0 or 1 alternatingly. You can create as many independent toggles as you want. 

use strict;
use warnings;

sub create_toggle {
    my $flag = 0;
    return sub { $flag = 1-$flag } # your favorite method here
}

my $toggle = create_toggle;

print $toggle->()."\n" for 1..10;

[download]

UPDATE: ...or like this 

use strict;
use warnings;
{
    package Toggler;
    sub new {
    my $flag =  0;
    return sub { $flag = 1-$flag }
    }
}

my $toggle = new Toggler;

print $toggle->()."\n" for 1..10;

[download]

In reply to Re: Boolean counter? by hdb
in thread Boolean counter? by DreamT

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