IntlChar::tolower

(PHP 7, PHP 8)

IntlChar::tolower — Make Unicode character lowercase

Опис

public static IntlChar::tolower(int|string $codepoint): int|string|null

The given character is mapped to its lowercase equivalent. If the character has no lowercase equivalent, the original character itself is returned.

Параметри

codepoint: Значення кодової точки типу int (наприклад 0x2603 для U+2603 SNOWMAN) або символ UTF-8 типу string (напр. "\u{2603}")

Значення, що повертаються

Returns the Simple_Lowercase_Mapping of the code point, if any; otherwise the code point itself. Returns null on failure.

Якщо кодова точка була передана як string в кодуванні UTF-8, то тип значення, що повертається — string, інакше ж повернеться int. Повертає null у разі невдачі.

Приклади

Приклад #1 Тестування різних кодових точок

<?php
var_dump(IntlChar::tolower("A"));
var_dump(IntlChar::tolower("a"));
var_dump(IntlChar::tolower("Φ"));
var_dump(IntlChar::tolower("φ"));
var_dump(IntlChar::tolower("1"));
var_dump(IntlChar::tolower(ord("A")));
var_dump(IntlChar::tolower(ord("a")));
?>

Поданий вище приклад виведе:

string(1) "a"
string(1) "a"
string(2) "φ"
string(2) "φ"
string(1) "1"
int(97)
int(97)

Прогляньте також

IntlChar::totitle() - Make Unicode character titlecase
IntlChar::toupper() - Make Unicode character uppercase
mb_strtolower() - Make a string lowercase

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User Contributed Notes 1 note

down

Patanjali ¶

4 years ago

The other function I wrote to replace mb_strtolower may not work properly, as it erroneously equated graphemes with codepoints.

tolower, like many IntlChar methods, works specifically on codepoints, so requires a codepoint iterator to isolate each.

Also, because in tolower, if there is no lowercase version of the codepoint, the supplied one is returned, so there is no need to specially test for alphabetic codepoints before conversion.

<?php 
function u_tolower($text=''){
// if blank, return blank (don't waste CPU cycles)
if($text==''){return'';}

// create the codepoint break iterator to identify the start of each codepoint
$iterator=IntlBreakIterator::createCodePointInstance();

// load the text
$iterator->setText($text);

// using a parts iterator to extract each codepoint itself, convert and append it to the new string
$newtext='';
foreach($iterator->getPartsIterator() as $codepoint){$newtext.=IntlChar::tolower($codepoint);}

// return converted text
return $newtext;
}
?>

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