mb_strimwidth
(PHP 4 >= 4.0.6, PHP 5)
mb_strimwidth — Get truncated string with specified width
Описание
string mb_strimwidth
( string $str
, int $start
, int $width
[, string $trimmarker
[, string $encoding
]] )
Truncates string str to specified width .
Список параметров
- str
-
The string being decoded.
- start
-
The start position offset. Number of characters from the beginning of string. (First character is 0)
- width
-
The width of the desired trim.
- trimmarker
-
A string that is added to the end of string when string is truncated.
- encoding
-
The encoding parameter is the character encoding. If it is omitted, the internal character encoding value will be used.
Возвращаемые значения
The truncated string. If trimmarker is set, trimmarker is appended to the return value.
Примеры
Пример #1 mb_strimwidth() example
<?php
$str = mb_strimwidth($str, 0, 40, "..>");
?>
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Коментарии
I see a lot of usage in the field where people rely on this function to truncate a string to a given length and append some chars at the end following example #1 in the above documentation.
While this works just fine with Western alphabets, it should be noted that a string's width is NOT necessarily the same as its length.
In Chinese, Japanese and Korean, some characters can be represented as full or half width, which may lead to unexpected results...
<?php
$str = ['English' => 'Switzerland',
'Half width' => 'ｽｲｽ',
'Full width' => 'スイス',
];
foreach ($str as $w => $s) {
printf("%-10s: %s (bytes=%d chars=%d width=%d)\nSubstring : %s\nTrim width: %s\n\n",
$w, $s,
strlen($s), mb_strlen($s), mb_strwidth($s),
mb_substr($s, 0, 3),
mb_strimwidth($s, 0, 3)
);
}
/* Output
# With ASCII, chars == width, so everything works as expected
English : Switzerland (bytes=11 chars=11 width=11)
Substring : Swi
Trim width: Swi
# With half-width katakanas, it works too
Half width: ｽｲｽ (bytes=9 chars=3 width=3)
Substring : ｽｲｽ
Trim width: ｽｲｽ
# Full-width katakanas are twice as wide, so we only get the 1st 'su' !
Full width: スイス (bytes=9 chars=3 width=6)
Substring : スイス
Trim width: ス
*/
>?
mb_strimwidth will only append "trim_marker" if the string is over the width.
*test code*
$HashTags = 'Results';
$socialmediatext = 'abcdefghijklmnopqrstuvwxyz';
for( $i=0; $i<=20; $i++ )
{
$socialmediatext .= '.';
$Twittext = mb_strimwidth($socialmediatext,0,35,$HashTags);
echo "<p>[".strlen($Twittext)."]$Twittext</p>";
}
*output*
[27]abcdefghijklmnopqrstuvwxyz.
[28]abcdefghijklmnopqrstuvwxyz..
[29]abcdefghijklmnopqrstuvwxyz...
[30]abcdefghijklmnopqrstuvwxyz....
[31]abcdefghijklmnopqrstuvwxyz.....
[32]abcdefghijklmnopqrstuvwxyz......
[33]abcdefghijklmnopqrstuvwxyz.......
[34]abcdefghijklmnopqrstuvwxyz........
[35]abcdefghijklmnopqrstuvwxyz.........
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results
[35]abcdefghijklmnopqrstuvwxyz..Results