IntlChar::tolower

(PHP 7)

IntlChar::tolower — Make Unicode character lowercase

Opis

public static IntlChar::tolower ( mixed $codepoint ) : mixed

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

Parametry

codepoint: Wartość typu integer dla punktu kodowego (np. 0x2603 dla U+2603 SNOWMAN) lub znak zakodowany jako string UTF-8 (np. "\u{2603}")

Zwracane wartości

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

Zwróconym typem będzie integer, chyba że codepoint przekazano jako łańcuch znaków UTF-8 - w tym wypadku zwrócony zostanie string.

Przykłady

Przykład #1 Testowanie różnych punktów kodowych


<?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")));
?>

Powyższy przykład wyświetli:

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

Zobacz też:

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 2 notes

down

Patanjali ¶

3 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;
}
?>

down

-1

Patanjali ¶

4 years ago


A function to convert a Unicode string to lowercase, directly replacing mb_strtolower, by converting one grapheme at a time:

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

 // for each grapheme
 $str='';
 for($i=0;$i<grapheme_strlen($text);$i++){
  // add to string if alpha, else as is
  $char=grapheme_substr($text,$i,1);
  $str.=(IntlChar::isalnum($char)?IntlChar::tolower($char):$char);
 }

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

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