Math::N...itCount(3)

💅 Math::NumSeq::DigitCount — the whole vibe ✨

okay so bestie, this page lives in the User Contributed Perl Documentation manual (that's the manual name, mwah 💖). It's called Math::NumSeq::DigitCount, and it counts how many of a given digit show up in a number. iconic behaviour honestly 🎀

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🌸 NAME 🌸

Math::NumSeq::DigitCount — count of a given digit. literally just that. no cap.

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✨ SYNOPSIS ✨

use Math::NumSeq::DigitCount;
my $seq = Math::NumSeq::DigitCount->new (radix => 10,
                                         digit => 9);
my ($i, $value) = $seq->next;

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🦋 DESCRIPTION 🦋

so the whole thing is: count how many of a given digit is in $i when you write $i out in a given radix. The default? counting how many 9s are in the decimal. obsessed 🫶

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, ...
starting i=0

for example i=19 has a single "9" so value=1. cute right 💜

the "radix" and "digit" options can pick a whole different number base or a different digit to count. Like, to count the 0-bits in binary:

# radix=>2, digit=>0
0, 0, 1, 0, 2, 1, 1, 0, 3, 2, 2, 1, 2, 1, 1, 0, 4, 3, 3, 2, ...
starting i=0

and listen, i=0 is treated as no digits at all, so it has value=0 for the count of 0-bits, and same energy in other bases when you're counting 0 digits. no notes ✨

option "digit => -1" gives the highest digit in the radix, ie. radix-1. That's the default, so if you pass "radix" the count is of its biggest digit. main character digit fr 👑

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💖 FUNCTIONS 💖

go peek at "FUNCTIONS" in Math::NumSeq for the behaviour common to all sequence classes. standard stuff bestie 🧚

• "$seq = Math::NumSeq::DigitCount->new (radix => $r, digit => $d)" — Create and return a new sequence object.
  • "digit" can be -1 to mean digit radix-1, the highest digit in the radix.

🍓 Random Access 🍓

• "$value = $seq->ith($i)" — Return how many of the given "digit" is in $i written in "radix".
• "$bool = $seq->pred($value)" — Return true if $value might occur as a digit count, which means simply "$value>=0".

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🌈 SEE ALSO 🌈

• Math::NumSeq
• Math::NumSeq::DigitLength
• Math::NumSeq::RadixWithoutDigit

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👑 HOME PAGE 👑

<http://user42.tuxfamily.org/math-numseq/index.html>

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🎀 LICENSE 🎀

Copyright 2010, 2011, 2012, 2013, 2014, 2016, 2017, 2019, 2020 Kevin Ryde

Math-NumSeq is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Math-NumSeq is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.

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bestie this one's perl v5.42.0, dated 2025-07-25 — that's the source/version and date, slay 💅✨

bye pookie, go count some digits 🦋💖