str_word_count
A simple multibyte-safe case-insensitive string comparison:
<?php
function mb_strcasecmp($str1, $str2, $encoding = null) {
if (null === $encoding) { $encoding = mb_internal_encoding(); }
return strcmp(mb_strtoupper($str1, $encoding), mb_strtoupper($str2, $encoding));
}
?>
Caveat: watch out for edge cases like "ß".
strcasecmp
(PHP 4, PHP 5)
strcasecmp — 大文字小文字を区別しないバイナリセーフな文字列比較を行う
説明
int strcasecmp
( string
$str1
, string $str2
)大文字小文字を区別しないバイナリセーフな文字列比較を行います。
パラメータ
-
str1 -
最初の文字列。
-
str2 -
次の文字列。
返り値
str1 が str2
より小さい場合は負、str1 が
str2 より大きい場合は正、等しい場合は 0
を返します。
例
例1 strcasecmp() の例
<?php
$var1 = "Hello";
$var2 = "hello";
if (strcasecmp($var1, $var2) == 0) {
echo '$var1 is equal to $var2 in a case-insensitive string comparison';
}
?>
参考
- strcmp() - バイナリセーフな文字列比較
- preg_match() - 正規表現によるマッチングを行う
- substr_compare() - 指定した位置から指定した長さの 2 つの文字列について、バイナリ対応で比較する
- strncasecmp() - バイナリセーフで大文字小文字を区別しない文字列比較を、最初の n 文字について行う
- stristr() - 大文字小文字を区別しない strstr
- substr() - 文字列の一部分を返す
add a note
User Contributed Notes
strcasecmp
chris at cmbuckley dot co dot uk
28-Dec-2011 04:59
alvaro at demogracia dot com
29-Jul-2010 05:35
Don't forget this is a single-byte function: in Unicode strings it'll provide incoherent results as soon as both strings differ only in case. There doesn't seem to exist a built-in multi-byte alternative so you need to write your own, taking into account both character encoding and collation.
27-Aug-2002 06:53
The sample above is only true on some platforms that only use a simple 'C' locale, where individual bytes are considered as complete characters that are converted to lowercase before being differentiated.
Other locales (see LC_COLLATE and LC_ALL) use the difference of collation order of characters, where characters may be groups of bytes taken from the input strings, or simply return -1, 0, or 1 as the collation order is not simply defined by comparing individual characters but by more complex rules.
Don't base your code on a specific non null value returned by strcmp() or strcasecmp(): it is not portable. Just consider the sign of the result and be sure to use the correct locale!