はじめに

PHPの標準関数をRubyで書いてみました。
簡単に書けそうなものだけパズル感覚で書いてます。

文字列操作編です。

引数と返り値の型はテーブルで記載しました。

str_contains($haystack, $needle)

PHP: str_contains - Manual


haystack	String
needle	String
return	TrueClass \| FalseClass

Ruby

haystack.include?(needle)

str_ends_with($haystack, $needle)

PHP: str_ends_with - Manual


haystack	String
needle	String
return	TrueClass \| FalseClass

Ruby

haystack.end_with?(needle)

str_getcsv ($string, $separator, $enclosure, $escape)

PHP: str_getcsv - Manual


string	String
separator	String
enclosure	String
escape	標準CSVライブラリでは指定不可 (2回続けて入力してエスケープ)
return	Array<String>

Ruby

require "csv"
CSV.parse_line(string, col_sep: separator, quote_char: enclosure)

str_ireplace($search, $replace, $subject, &$count)

PHP: str_ireplace - Manual


search	String
replace	String
subject	String
count	Integer
return	String

Ruby

count = 0
subject.gsub(Regexp.new(Regexp.escape(search), Regexp::IGNORECASE)) {count += 1; replace}

str_pad($string, $length, $pad_string, $pad_type)

PHP: str_pad - Manual


string	String
length	Integer
pad_string	String
pad_type	STR_PAD_RIGHT
return	String

Ruby

string.ljust(length, pad_string)


string	String
length	Integer
pad_string	String
pad_type	STR_PAD_LEFT
return	String

Ruby

string.rjust(length, pad_string)


string	String
length	Integer
pad_string	String
pad_type	STR_PAD_BOTH
return	String

Ruby

string.center(length, pad_string)

str_repeat($string, $times)

PHP: str_repeat - Manual


string	String
times	Integer
return	String

Ruby

string * times

str_replace($search, $replace, $subject, &$count)

PHP: str_replace - Manual


search	String
replace	String
subject	String
count	Integer
return	String

Ruby

count = 0
subject.gsub(Regexp.new(Regexp.escape(search))) {count += 1; replace}

str_rot13($string)

PHP: str_rot13 - Manual


string	String
return	String

Ruby

string.tr("a-zA-Z", "n-za-mN-ZA-M")

str_shuffle($string)

PHP: str_shuffle - Manual


string	String
return	String

Ruby

string.chars.shuffle.join

str_split($string, $length)

PHP: str_split - Manual


string	String
length	Integer ※1以上
return	String

Ruby

string.each_char.each_slice(length).map(&:join)

str_starts_with($haystack, $needle)

PHP: str_starts_with - Manual


haystack	String
needle	String
return	TrueClass \| FalseClass

Ruby

haystack.start_with?(needle)

str_word_count($string, $format, $characters)

PHP: str_word_count - Manual


string	String
format	0
characters	String
return	Integer

Ruby

string.match(/^[-']*(.*?)-*$/)[1].scan(/[-'a-zA-Z]+/).count


string	String
format	1
characters	String
return	Array<String>

Ruby

string.match(/^[-']*(.*?)-*$/)[1].scan(/[-'a-zA-Z]+/)

strcasecmp($str1, $str2)

PHP: strcasecmp - Manual


str1	String
str2	String
return	Integer

Ruby

str1.casecmp(str2)

※返却値は-1, 0, 1のいずれかなので注意

strcmp($str1, $str2)

PHP: strcmp - Manual


str1	String
str2	String
return	Integer

Ruby

str1 <=> str2

※返却値は-1, 0, 1のいずれかなので注意

strcspn($string, $characters, $offset, $length)

PHP: strcspn - Manual


string	String
characters	String
offset	Integer
length	Integer ※0以上
return	Integer

Ruby

string = string[offset, length]
string.chars.each_with_index.find { |c, _| characters.include?(c) }&.at(1) || string.length

stripos($haystack, $needle, $offset)

PHP: stripos - Manual


haystack	String
needle	String
offset	Integer
return	String \| FalseClass

Ruby

haystack.downcase.index(needle.downcase, offset)

stristr($haystack, $needle, $before_needle)

PHP: stristr - Manual


haystack	String
needle	String
before_needle	FalseClass
return	String \| FalseClass

Ruby

haystack.chars.each_with_index.find { |c, _| c.casecmp?(needle) }.then { |_, i| i ? haystack[i..] : false }


haystack	String
needle	String
before_needle	TrueClass
return	String \| FalseClass

Ruby

haystack.chars.each_with_index.find { |c, _| c.casecmp?(needle) }.then { |_, i| i ? haystack[0, i] : false }

strlen($string)

PHP: strlen - Manual


string	String
return	Integer

Ruby

string.length

strncasecmp($str1, $str2, $length)

PHP: strncasecmp - Manual


str1	String
str2	String
length	Integer
return	Integer

Ruby

str1[0, length].casecmp(str2[0, length])

※返却値は-1, 0, 1のいずれかなので注意

strncmp($str1, $str2, $length)

PHP: strncmp - Manual


str1	String
str2	String
length	Integer
return	Integer

Ruby

str1[0, length] <=> str2[0, length]

※返却値は-1, 0, 1のいずれかなので注意

strpbrk($string, $characters)

PHP: strpbrk - Manual


string	String
characters	String
return	String \| FalseClass

Ruby

string.chars.each_with_index.find { |c, _| characters.include?(c) }.then { |_, i| i ? string[i..] : false }

strpos($haystack, $needle, $offset)

PHP: strpos - Manual


haystack	String
needle	String
offset	Integer
return	String \| FalseClass

Ruby

haystack.index(needle, offset)

strrchr($haystack, $needle)

PHP: strrchr - Manual


haystack	String
needle	String
return	String \| FalseClass

Ruby

haystack.chars.reverse.each_with_index.find { |c, _| c == needle.chr }.then { |_, i| i ? haystack[-i-1..] : false }

strrev($string)

PHP: strrev - Manual


string	String
return	String

Ruby

string.reverse

strripos($haystack, $needle, $offset)

PHP: strripos - Manual


haystack	String
needle	String
offset	Integer ※0以上
return	String \| FalseClass

Ruby

haystack[offset..].downcase.rindex(needle.downcase)&.+(offset) || false


haystack	String
needle	String
offset	Integer ※0未満
return	String \| FalseClass

Ruby

haystack.downcase.rindex(needle.downcase, offset) || false

strrpos($haystack, $needle, $offset)

PHP: strrpos - Manual


haystack	String
needle	String
offset	Integer ※0以上
return	String \| FalseClass

Ruby

haystack[offset..].rindex(needle)&.+(offset) || false


haystack	String
needle	String
offset	Integer ※0未満
return	String \| FalseClass

Ruby

haystack.rindex(needle, offset) || false

strspn($string, $characters, $offset, $length)

PHP: strspn - Manual


string	String
characters	String
offset	Integer
length	Integer ※0以上
return	Integer

Ruby

string = string[offset, length]
string.chars.each_with_index.find { |c, _| !characters.include?(c) }&.at(1) || string.length

strstr($haystack, $needle, $before_needle)

PHP: strstr - Manual


haystack	String
needle	String
before_needle	FalseClass
return	String \| FalseClass

Ruby

haystack.chars.each_with_index.find { |c, _| c == needle }.then { |_, i| i ? haystack[i..] : false }


haystack	String
needle	String
before_needle	TrueClass
return	String \| FalseClass

Ruby

haystack.chars.each_with_index.find { |c, _| c == needle }.then { |_, i| i ? haystack[0, i] : false }

strtolower($string)

PHP: strtolower - Manual


string	String
return	String

Ruby

string.downcase

strtoupper($string)

PHP: strtoupper - Manual


string	String
return	String

Ruby

string.upcase

strtr($string, $from, $to)

PHP: strtr - Manual


string	String
from	String
to	String
return	String

Ruby

limit = [from, to].map(&:length).min
string.tr(from[0, limit], to[0, limit])

strtr($string, $replace_pairs)

PHP: strtr - Manual


string	String
replace_pairs	Hash<String, String>
return	String

Ruby

string.gsub(Regexp.new(replace_pairs.keys.map { |s| Regexp.escape(s) }.join('|'))) { |m| replace_pairs[m] }

参考文献

Class array (Ruby 3.0.0 リファレンスマニュアル). (n.d.). docs.ruby-lang.org. Retrieved March 30, 2021, from https://docs.ruby-lang.org/ja/latest/class/Array.html
Class CSV (Ruby 3.0.0 リファレンスマニュアル). (n.d.). docs.ruby-lang.org. Retrieved March 30, 2021, from https://docs.ruby-lang.org/ja/latest/class/CSV.html
Class Regexp (Ruby 3.0.0 リファレンスマニュアル). (n.d.). docs.ruby-lang.org. Retrieved March 30, 2021, from https://docs.ruby-lang.org/ja/latest/class/Regexp.html
Class string (Ruby 3.0.0 リファレンスマニュアル). (n.d.). docs.ruby-lang.org. Retrieved March 30, 2021, from https://docs.ruby-lang.org/ja/latest/class/String.html
Module enumerable (Ruby 3.0.0 リファレンスマニュアル). (n.d.). docs.ruby-lang.org. Retrieved March 30, 2021, from https://docs.ruby-lang.org/ja/latest/class/Enumerable.html
Str_contains. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-contains.php
Str_ends_with. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-ends-with.php
Str_getcsv. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-getcsv.php
Str_ireplace. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-ireplace.php
Str_pad. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-pad.php
Str_repeat. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-repeat.php
Str_replace. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-replace.php
Str_rot13. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-rot13.php
Str_shuffle. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-shuffle.php
Str_split. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-split.php
Str_starts_with. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-starts-with.php
Str_word_count. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.str-word-count.php
Strcasecmp. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strcasecmp.php
Strcmp. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strcmp.php
Strcspn. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strcspn.php
Stripos. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.stripos.php
Stristr. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.stristr.php
Strlen. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strlen.php
Strncasecmp. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strncasecmp.php
Strncmp. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strncmp.php
Strpbrk. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strpbrk.php
Strpos. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strpos.php
Strrchr. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strrchr.php
Strrev. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strrev.php
Strripos. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strripos.php
Strrpos. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strrpos.php
Strspn. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strspn.php
Strstr. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strstr.php
Strtolower. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strtolower.php
Strtoupper. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strtoupper.php
Strtr. (n.d.). PHP: Hypertext Preprocessor. Retrieved March 30, 2021, from https://www.php.net/manual/ja/function.strtr.php