(PHP 4, PHP 5)
strtolower — 将字符串转化为小写
$str
)
将 string 中所有的字母字符转换为小写并返回。
注意 “字母” 与当前所在区域有关。例如，在默认的 “C” 区域，字符 umlaut-A（?）就不会被转换。
str
输入字符串。
返回转换后的小写字符串。
Example #1 strtolower() 范例
<?php
$str = "Mary Had A Little Lamb and She LOVED It So";
$str = strtolower($str);
echo $str; // 打印 mary had a little lamb and she loved it so
?>
Note: 此函数可安全用于二进制对象。
maxim at inbox dot ru (2012-07-01 08:35:10)
Nice idea to use static vars, here is my solution, i think, it is not very nice, when two very simular functions are separate. So :
<?php
function tocase($s,$up=false)
{
global $chars_hi, $chars_lo;
return $up?strtr($s, $chars_lo, $chars_hi):strtr($s, $chars_hi,$chars_lo);
}
?>
Just use second param when u need to uppercase, by default (false) it makes low, nice speed and small space :)
utilmind at gmail (2012-05-17 17:46:44)
Everyone knows that strtolower/strtoupper does not translate cyrillic charactes (cp1251 code page). But I just was surprised that strtolower works twice(!) slower that translating characters with "strtr()".
Here is what I use to translate cyrillic (works for Russian, Ukrainian, Belorussian and cyrillic balcan languages, like Serbian etc):
<?php
// Arrays (REMOVE THE LINE BREAKS! THIS NOT WON'T BE POSTED WITH SUCH LONG LINES!)
$chars_hi = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ
АБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯЁ??????????????';
$chars_lo = 'abcdefghijklmnopqrstuvwxyz
абвгдежзийклмнопрстуфхцчшщъыьэюяё??????????????';
// functions
function uppercase($s) {
global $chars_hi, $chars_lo;
return strtr($s, $chars_lo, $chars_hi);
}
function lowercase($s) {
global $chars_hi, $chars_lo;
return strtr($s, $chars_hi, $chars_lo);
}
?>
Remember, it works TWICE FASTER than strtoupper/strtolower! So maybe someone will would like to translate the arrays for another code pages different than cp1251
on at niepodam dot pl (2011-10-24 07:23:38)
If the input string is in different language that server locale, then you should use mb_strtolower() function.
RCube (2011-03-31 16:57:54)
To convert an entire array to lower, I prefer this method;
<?php
function arraytolower(array $array, $round = 0){
return unserialize(strtolower(serialize($array)));
}
?>
3 lines of code seem a lot less overhead than 10-40.
If there's any intrinsic problem with this method, please post it.
marcin at maydesign dot pl (2010-06-22 15:16:55)
strtolower(); doesn't work for polish chars
<?php strtolower("m?kA"); ?>
will return: m?ka;
the best solution - use mb_strtolower()
<?php mb_strtolower("m?kA",'UTF-8'); ?>
will return: m?ka
sanderwind at gmail dot com (2010-06-11 06:03:27)
Very easy way to only make the first character lowercase:
<?php
function lcfirst($string) {
$string{0} = strtolower($string{0});
return $string;
}
?>
ewertonp at hotmail dot com (2009-09-30 11:50:02)
Here is my solution to lowercase strings Latin strings with accents. In this case I've used Brazilian Portuguese locale:
<?PHP
setlocale(LC_ALL, 'pt_BR');
echo strtolower('??????');
// output: éá?úí?
echo ucfirst(strtolower('é?????'));
// output: ?á?úí?
?>
leha_grobov (2009-06-25 20:03:35)
the strtolower version to support most amount of languages including russian, french and so on:
<?php
function strtolower_utf8($string){
$convert_to = array(
"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u",
"v", "w", "x", "y", "z", "à", "á", "?", "?", "?", "?", "?", "?", "è", "é", "ê", "?", "ì", "í", "?", "?",
"?", "?", "ò", "ó", "?", "?", "?", "?", "ù", "ú", "?", "ü", "?", "а", "б", "в", "г", "д", "е", "ё", "ж",
"з", "и", "й", "к", "л", "м", "н", "о", "п", "р", "с", "т", "у", "ф", "х", "ц", "ч", "ш", "щ", "ъ", "ы",
"ь", "э", "ю", "я"
);
$convert_from = array(
"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U",
"V", "W", "X", "Y", "Z", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?",
"?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "А", "Б", "В", "Г", "Д", "Е", "Ё", "Ж",
"З", "И", "Й", "К", "Л", "М", "Н", "О", "П", "Р", "С", "Т", "У", "Ф", "Х", "Ц", "Ч", "Ш", "Щ", "Ъ", "Ъ",
"Ь", "Э", "Ю", "Я"
);
return str_replace($convert_from, $convert_to, $string);
}
?>
Khigashi (2009-06-22 14:53:51)
Here is my code, I made because of the accents contained in the latin languages [like the Portuguese of Brazil =)]
<?php
function deepLower($texto){
//Letras minúsculas com acentos
$texto = strtr($texto, "
?????????ABCDEFGHIJKLMNOPRSTUWYZQ
XVЁЙЦУКЕНГШЩЗХЪФЫВАПРОЛДЖЭЯЧСМИТЬБЮ
???????????????????????
", "
????ńó???abcdefghijklmnoprstuwyzq
xvёйцукенгшщзхъфывапролджэячсмитьбю
?àá??êèé??íì???òó??ùúü?
");
return strtolower($texto);
}
?>
hans111 {AT} yahoo {DOT} com (2009-05-13 15:02:25)
Could be useful, if mb string library is not available for whatever the reason:
<?php
function utf8_strtolower($string) {
return utf8_encode(strtolower(utf8_decode($string)));
}
##equally.....
function utf8_ucfirst($string) {
return utf8_encode(ucfirst(utf8_decode($string)));
}
#.....etc...
?>
It has worked for me, just make sure you feed the functions with the proper encoded text (utf-8)
[These functions] only work when translation is between common characters in ISO 8859-1 and UTF-8, that means they will work well with western languages but not cyrillic or asian.
coder at bulgaria dot bg (2009-04-03 16:08:15)
for cyrillic and UTF 8 use mb_convert_case
exampel
<?php
$string = "Австралия";
$string = mb_convert_case($string, MB_CASE_LOWER, "UTF-8");
echo $string;
//output is: австралия
?>
ghutix6 at gmail dot com (2009-03-15 01:50:45)
Here is function for working polish lower letters (plus example):
<?php
function lower_pl($str)
{
return strtr($str, "?????????ABCDEFGHIJKLMNOPRSTUWYZQXV", "????ńó???abcdefghijklmnoprstuwyzqxv");
}
$word ="???TKO";
$word = lower_pl ($word);
echo ("<p>$word</p>");
?>
This will turn into: <p>?ó?tko</p>.
dbers26 at gmail dot com (2009-01-07 13:34:54)
the function arraytolower will create duplicate entries since keys are case sensitive.
<?php
$array = array('test1' => 'asgAFasDAAd', 'TEST2' => 'ASddhshsDGb', 'TeSt3 '=> 'asdasda@asdadadASDASDgh');
$array = arraytolower($array);
?>
/*
Array
(
[test1] => asgafasdaad
[TEST2] => ASddhshsDGb
[TeSt3] => asdasda@asdadadASDASDgh
[test2] => asddhshsdgb
[test3] => asdasda@asdadadasdasdgh
)
*/
I prefer this method
<?php
function arraytolower($array, $include_leys=false) {
if($include_leys) {
foreach($array as $key => $value) {
if(is_array($value))
$array2[strtolower($key)] = arraytolower($value, $include_leys);
else
$array2[strtolower($key)] = strtolower($value);
}
$array = $array2;
}
else {
foreach($array as $key => $value) {
if(is_array($value))
$array[$key] = arraytolower($value, $include_leys);
else
$array[$key] = strtolower($value);
}
}
return $array;
}
?>
which when used like this
<?php
$array = $array = array('test1' => 'asgAFasDAAd', 'TEST2' => 'ASddhshsDGb', 'TeSt3 '=> 'asdasda@asdadadASDASDgh');
$array1 = arraytolower($array);
$array2 = arraytolower($array,true);
print_r($array1);
print_r($array2);
?>
will give output of
Array
(
[test1] => asgafasdaad
[TEST2] => asddhshsdgb
[TeSt3] => asdasda@asdadadasdasdgh
)
Array
(
[test1] => asgafasdaad
[test2] => asddhshsdgb
[test3] => asdasda@asdadadasdasdgh
)
s0urce at anonyme dot com (2008-10-23 03:05:23)
for someone who needs - arraytolower:
<?php
function arraytolower($array,$round = 0){
foreach($array as $key => $value){
if(is_array($value)) $array[strtolower($key)] = $this->arraytolower($value,$round+1);
else $array[strtolower($key)] = strtolower($value);
}
return $array;
}
?>
converts the whole array in a levels. keys and values.
rodrigoATsistemasparainternetDOTcomDOTbr (2008-09-09 18:25:47)
<?php
function fullLower($str){
// convert to entities
$subject = htmlentities($str,ENT_QUOTES);
$pattern = '/&([a-z])(uml|acute|circ';
$pattern.= '|tilde|ring|elig|grave|slash|horn|cedil|th);/e';
$replace = "'&'.strtolower('\\1').'\\2'.';'";
$result = preg_replace($pattern, $replace, $subject);
// convert from entities back to characters
$htmltable = get_html_translation_table(HTML_ENTITIES);
foreach($htmltable as $key => $value) {
$result = ereg_replace(addslashes($value),$key,$result);
}
return(strtolower($result));
}
echo fullLower("? ? ? ? ???");
//results ? é ò ? úù?
//adapted from fullUpper on strtoupper manual
?>
concepton at gmail dot com (2008-08-10 21:50:15)
comment to "alexfort at list dot ru"
i think better to use this one
<?php
function strtolower_ru($text) {
$alfavitlover = array('ё','й','ц','у','к','е','н','г', 'ш','щ','з','х','ъ','ф','ы','в', 'а','п','р','о','л','д','ж','э', 'я','ч','с','м','и','т','ь','б','ю');
$alfavitupper = array('Ё','Й','Ц','У','К','Е','Н','Г', 'Ш','Щ','З','Х','Ъ','Ф','Ы','В', 'А','П','Р','О','Л','Д','Ж','Э', 'Я','Ч','С','М','И','Т','Ь','Б','Ю');
return str_replace($alfavitupper,$alfavitlover,strtolower($text));
}
?>
alexfort at list dot ru (2008-08-04 05:43:43)
<?php
//solution to the Cyrillic and uft-8
function strtolower_Cyrillic($word) {
$alfavitlover = explode(',', 'ё,й,ц,у,к,е,н,г,ш,щ,з,х,ъ,ф,ы,
в,а,п,р,о,л,д,ж,э,я,ч,с,м,и,т,ь,б,ю');
$alfavitupper = explode(',', 'Ё,Й,Ц,У,К,Е,Н,Г,Ш,Щ,З,Х,Ъ,Ф,Ы,
В,А,П,Р,О,Л,Д,Ж,Э,Я,Ч,С,М,И,Т,Ь,Б,Ю');
for($wr=0;$wr<=count($alfavitlover);$wr++) {
$word = str_replace($alfavitupper[$wr], $alfavitlover[$wr], $word);
}
return $word;
}
echo strtolower_Cyrillic('СаШа+МаШа');
?>
tushar at sel2in dot com (2008-07-28 08:57:06)
Quick and works for accented characters like á
Tested on linux and win apache+php5
<?php
function strtolower2($s){
$ln = strlen($s);
$ln1 = $ln -1;
for($i=0; $i < $ln; $i++){
$k = ord(substr($s, $i, 1));
if($k>=65 && $k <= 90){
if($i > 0){
$l1 = substr($s, 0, $i);
}else{
$l1 ='';
}
$l1 = $l1 . chr($k+32);
if($i < $ln1){
$l1 = $l1 . substr($s, $i + 1);
}
$s = $l1;
}
}
return $s;
}
?>
Piotr (2008-03-10 01:24:14)
///charset=iso-8859-2
function strtolower_iso8592($string)
{
$low=array("ˇ" => "±", "?" => "?", "?" => "?", "?" => "?", "?" => "ó", "?" => "?", "?" => "?", "?" => "?", "?" => "ń");
return strtolower(strtr($string,$low));
}
toringe at infostill dot com (2007-10-25 15:27:14)
This will work for all languages using ISO8859_1 - more code than many other but fast.
<?php
function strtolower_iso8859_1($s){
$i = strlen($s);
while ($i > 0) {
--$i;
$c =ord($s[$i]);
if (($c & 0xC0) == 0xC0) {
// two most significante bits on
if (($c != 215) and ($c != 223)){ // two chars OK as is
// to get lowercase set 3. most significante bit if needed:
$s[$i] = chr($c | 0x20);
}
}
}
return strtolower($s);
}
?>
patricia at steuerungb dot de (2007-10-17 06:29:28)
When you're not sure, how the current locale is set, you might find the following function useful. It's strtolower for utf8-formatted text:
<?php
function strtolower_utf8($inputString) {
$outputString = utf8_decode($inputString);
$outputString = strtolower($outputString);
$outputString = utf8_encode($outputString);
return $outputString;
}
?>
It's not suitable for every occasion, but it surely gets in handy. I use it for lowering German 'Umlauts' like ? and ?.
mr dot blober at gmail dot com (2007-06-16 11:39:35)
simple example for Polish characters
<?php
function strtolower_pl($str)
{
return strtr(strtolower($str), '[?????????]', '[????ńó???]');
}
?>
rok dot kralj at gmail dot com (2007-06-04 11:49:33)
Slovenian characters
<?php
function strtolower_slovenian($string)
{
$low=array("?" => "?", "?" => "?", "?" => "?");
return strtolower(strtr($string,$low));
}
?>
marco at recchiuti dot it (2007-05-22 00:43:55)
Maybe it is not so elegant, but it Works.
It's just a fast Idea and it is what I need.
Any hacks for other characters (link !, ? etc etc) should help.
function RemoveShouting($string)
{
$frase = "";
$astri = explode(".", $string);
foreach ($astri as $elem)
$frase .= " ".ucfirst(trim(strtolower($elem))).". ";
return trim($frase);
}
Cheers!
M
mario dot kostelac at gmail dot com (2007-04-29 04:42:33)
This is strtolower function for Croatian characters:
function strToLowerCro($string){
$string = strtolower($string);
$patterns[0] = '/?/';
$patterns[1] = '/?/';
$patterns[2] = '/?/';
$patterns[3] = '/?/';
$patterns[4] = '/?/';
$replacements[0] = '?';
$replacements[1] = '?';
$replacements[2] = '?';
$replacements[3] = '?';
$replacements[4] = '?';
$string = preg_replace($patterns, $replacements, $string);
return $string;
}
Enjoy...
HQ063 (2007-03-31 12:37:53)
Similar to last function, but for spanish
function strtolower_es($string)
{
$low=array("?" => "á", "?" => "é", "?" => "í", "?" => "ó", "?" => "ú", "?" => "ü", "?" => "?");
return strtolower(strtr($string,$low));
}
Din?er Akay (2006-12-20 02:32:50)
Turkish Character
<?php
function strtolower_tr($string)
{
$low=array("?" => "ü", "?" => "?", "?" => "?", "?" => "?", "?" => "?", "?" => "i", "I" => "?");
return strtolower(strtr($string,$low));
}
?>
Enzo_01 at abv dot bg (2006-11-06 23:31:20)
two functions what works with cyrilic text
function cyr_strtolower($a) {
$offset=32;
$m=array();
for($i=192;$i<224;$i++)$m[chr($i)]=chr($i+$offset);
return strtr($a,$m);
}
function cyr_strtoupper($a) {
$offset=32;
$m=array();
for($i=192;$i<224;$i++)$m[chr($i+$offset)]=chr($i);
return strtr($a,$m);
}
ex:
cyr_strtoupper("абвгде"); // АБВГДЕ
cyr_strtolower("АБВГДЕ"); // абвгде
eduardor2k at redr2k dot com (2006-08-08 14:34:19)
I changed it a bit and i found that it's better to put everything in lowercase, and rebuild the text the same way a teacher corrects a text, for now it only checks that the first letter after a point "." must be
in upper case.
function RemoveShouting($string)
{
$string = strtolower(trim($string));
for($i=0;$i<strlen($string);$i++){
if($i==0){$string[$i] = strtoupper($string[$i]);}
if($string[$i] == "."){
while($string[$i+1] == " "){
$i++;
}
$string[$i+1] = strtoupper($string[$i+1]);
$i++;
}
}
return $string;
}
this function would change:
Hi mi name is PETER. SOME TIMES I FORGOT TO DISABLE CAPS LOCK.
into:
Hi mi name is peter. Some times i forgot to disable caps lock.
spiceee ddotty spiceee com (2006-03-06 16:53:02)
If you ever need to strtolower a string with href tags on it and doesn't want to mess with the characters inside a tag, this is for you.
<?php
function loweroutsidetags ($str) {
$chars = preg_split ("//", $str);
$tolower = true;
$str = '';
foreach ($chars as $k) {
if ($k == '<') { $tolower = false; }
if ($tolower) { $k = strtolower ($k); }
$str .= $k;
if ($k == '>') { $tolower = true; }
}
return $str;
}
?>
this:
echo loweroutsidetags('aALalala <a href="?q=CASEsENSITIVINESSinURLSareSTUPID">')
will give:
aalalala <a href="?q=CASEsENSITIVINESSinURLSareSTUPID">
red at iklanumum dot com (2006-02-23 18:43:45)
I've seen this as a common use from script developers, so I would like to share the alternative way to compare 2 string (CASE INSENSITIVE) without using strtolower for faster process.
Use strcasecmp() for comparison purpose rather than comparing uncertain case of 2 string variables, because strcasecmp() is approximately 60% faster, moreover, the greater its string length the greater the difference,!
Ex. case :
$var1; -> could be a mixture of upper & lower case
$var2; -> could be a mixture of upper & lower case
To compare whether $var1 is exactly the same as $var2 (case insensitive manner):
Use -> if (strcasecmp($var1,$var2)==0)
rather than -> if (strtolower($var1)==strtolower($var2))
Patrick (2006-01-19 10:57:21)
If you're considering using the below unhtmlentities function from phpContrib, I would suggest this one as an alternative:
<?php
function unhtmlentities($string)
{
// replace numeric entities
$string = preg_replace('~&#x([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $string);
$string = preg_replace('~&#([0-9]+);~e', 'chr(\\1)', $string);
// replace literal entities
$trans_tbl = get_html_translation_table(HTML_ENTITIES);
$trans_tbl = array_flip($trans_tbl);
return strtr($string, $trans_tbl);
}
?>
That was copied exactly from the html_entity_decode manual page. It'll handle numeric entities correctly, the below function won't.
fackelkind (2006-01-11 00:03:01)
Nifty? :D
<?php
function is_lowercase ($str){
return ($str == strtolower ($str));
}
?>
mhuggins57 at yahoo dot com (2005-07-19 16:04:32)
There's a ucfirst "function" to make the first character uppercase, but there's no "lcfirst" function to make the first character lowercase. Here's my own code to accomplish this.
<?
function lcfirst($str) {
return strtolower(substr($str, 0, 1)) . substr($str, 1);
}
?>
I found this particularly useful for generating XML nodes with the Reflection class.
kmcdermott at perimeterinstitute dot ca (2004-12-08 13:04:05)
To do case insensitive comparisons in a database, strtolower() can be a quick and dirty solution:
$Sql = "SELECT * FROM tablename WHERE LOWER(column_name) = '".strtolower($my_var)."'";
phpContrib (A T) esurfers d o t c o m (2004-09-24 11:07:10)
<?php
$b=html_entity_decode(strtolower(htmlentities($a)));
?>
will convert to lowercase most accented vocals
(it will convert ? into À into à into ?)
This is not fast and clean code, it is just a quick oneliner to help you if you need a quick way to do it
?
Users with older versions of PHP can use:
$b=unhtmlentities(strtolower(htmlentities($a)));
// with unhtmlentities() as defined in the html_entity_decode() manual page:
function unhtmlentities ($string) {
$trans_tbl =get_html_translation_table (HTML_ENTITIES );
$trans_tbl =array_flip ($trans_tbl );
return strtr ($string ,$trans_tbl );
}
bkimble at ebaseweb dot com (2003-01-19 22:39:44)
Heres a small function I wrote to stop people from submitting data that is ALL IN CAPS SO THEY CAN GET MORE ATTENTION THAT THE REST OF THE USER SUBMITTED DATA on my website :) If you can make it better, by all means do so. This function splits up words delimited by a space, and makes only the first letter of each word capitalized. You can easily modify it so it's only the very first word of the string. I've also added some exceptions so you don't make things like roman numerals look like "Iii" or "Xcmii" or something.
function RemoveShouting($string)
{
$lower_exceptions = array(
"to" => "1", "a" => "1", "the" => "1", "of" => "1"
);
$higher_exceptions = array(
"I" => "1", "II" => "1", "III" => "1", "IV" => "1",
"V" => "1", "VI" => "1", "VII" => "1", "VIII" => "1",
"XI" => "1", "X" => "1"
);
$words = split(" ", $string);
$newwords = array();
foreach ($words as $word)
{
if (!$higher_exceptions[$word]) $word = strtolower($word);
if (!$lower_exceptions[$word]) $word[0] = strtoupper($word[0]);
array_push($newwords, $word);
}
return join(" ", $newwords);
}
BK
tty01_at_rambler_dot_ru (2002-09-19 19:58:52)
Another solution for Double-Byte-Characters, based on iconv() functions, not sensible to the current locale, works on win32.
/* Converts charset */
function myConvertCharset($str, $from, $to)
{
if(@function_exists('iconv'))
{
return iconv($from, $to, $str);
}
else if(@function_exists('recode_string'))
{
return recode_string($from . '..' . $to, $str);
}
else
{
print "function iconv not exists";
return $str;
}
}
/* Converts a string to lowercase */
function my_strtolower($s)
{
$t = "windows-1251";
$d = "UTF-8";
return myConvertCharset(strtolower(myConvertCharset($s, $d, $t)), $t, $d);
}
print my_strtolower("СЛОВО Uppercase");
(2002-09-12 17:17:13)
This function is sensible to the current locale, namely the LC_CTYPE category (the default LC_CTYPE category is set from the LANG environment variable or by an explicit LC_CTYPE setting, but it can be overriden by the LC_ALL environment setting). If no locale setting is done in the enironment, the default locale will be C, for which the lowercase/uppercase conversion is based on the default character set of the system: this may convert only ASCII letters, or also ISO-8859-1 letters depending on the system...