strtolower
(PHP 4, PHP 5)
strtolower — Make a string lowercase
Description
string strtolower
( string
$str
)
Returns string with all alphabetic characters
converted to lowercase.
Note that 'alphabetic' is determined by the current locale. This means that in i.e. the default "C" locale, characters such as umlaut-A (Ä) will not be converted.
Parameters
-
str -
The input string.
Return Values
Returns the lowercased string.
Examples
Example #1 strtolower() example
<?php
$str = "Mary Had A Little Lamb and She LOVED It So";
$str = strtolower($str);
echo $str; // Prints mary had a little lamb and she loved it so
?>
Notes
Note: This function is binary-safe.
See Also
- strtoupper() - Make a string uppercase
- ucfirst() - Make a string's first character uppercase
- ucwords() - Uppercase the first character of each word in a string
- mb_strtolower() - Make a string lowercase
- addcslashes
- addslashes
- bin2hex
- chop
- chr
- chunk_split
- convert_cyr_string
- convert_uudecode
- convert_uuencode
- count_chars
- crc32
- crypt
- echo
- explode
- fprintf
- get_html_translation_table
- hebrev
- hebrevc
- hex2bin
- html_entity_decode
- htmlentities
- htmlspecialchars_decode
- htmlspecialchars
- implode
- join
- lcfirst
- levenshtein
- localeconv
- ltrim
- md5_file
- md5
- metaphone
- money_format
- nl_langinfo
- nl2br
- number_format
- ord
- parse_str
- printf
- quoted_printable_decode
- quoted_printable_encode
- quotemeta
- rtrim
- setlocale
- sha1_file
- sha1
- similar_text
- soundex
- sprintf
- sscanf
- str_getcsv
- str_ireplace
- str_pad
- str_repeat
- str_replace
- str_rot13
- str_shuffle
- str_split
- str_word_count
- strcasecmp
- strchr
- strcmp
- strcoll
- strcspn
- strip_tags
- stripcslashes
- stripos
- stripslashes
- stristr
- strlen
- strnatcasecmp
- strnatcmp
- strncasecmp
- strncmp
- strpbrk
- strpos
- strrchr
- strrev
- strripos
- strrpos
- strspn
- strstr
- strtok
- strtolower
- strtoupper
- strtr
- substr_compare
- substr_count
- substr_replace
- substr
- trim
- ucfirst
- ucwords
- vfprintf
- vprintf
- vsprintf
- wordwrap
Коментарии
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
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)."'";
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($str, 1);
}
?>
I found this particularly useful for generating XML nodes with the Reflection class.
If you're considering using the below unhtmlentities function from phpContrib, I would suggest this one as an alternative:
<?php
function unhtmlentities($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, $trans_tbl);
}
?>
That was copied exactly from the html_entity_decode manual page. It'll handle numeric entities correctly, the below function won't.
Maybe it is not so elegant, but it Works.
It's just a fast Idea and it is what I need.
Any hacks for other characters (link !, ? etc etc) should help.
function RemoveShouting($string)
{
$frase = "";
$astri = explode(".", $string);
foreach ($astri as $elem)
$frase .= " ".ucfirst(trim(strtolower($elem))).". ";
return trim($frase);
}
Cheers!
M
Slovenian characters
<?php
function strtolower_slovenian($string)
{
$low=array("Č" => "č", "Ž" => "ž", "Š" => "š");
return strtolower(strtr($string,$low));
}
?>
When you're not sure, how the current locale is set, you might find the following function useful. It's strtolower for utf8-formatted text:
<?php
function strtolower_utf8($inputString) {
$outputString = utf8_decode($inputString);
$outputString = strtolower($outputString);
$outputString = utf8_encode($outputString);
return $outputString;
}
?>
It's not suitable for every occasion, but it surely gets in handy. I use it for lowering German 'Umlauts' like ä and ö.
<?php
function fullLower($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("Ã É Ò Õ ÚÙÛ");
//results ã é ò õ úùû
//adapted from fullUpper on strtoupper manual
?>
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
)
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
?>
strtolower(); doesn't work for polish chars
<?php strtolower("mĄkA"); ?>
will return: mĄka;
the best solution - use mb_strtolower()
<?php mb_strtolower("mĄkA",'UTF-8'); ?>
will return: mąka
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.
It is worth noting that<?php
var_dump(strtolower(null))
?>
returns:
string(0) ""