mb_strimwidth

(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)

mb_strimwidth — Get truncated string with specified width

Beschreibung

mb_strimwidth(
    string $string,
    int $start,
    int $width,
    string $trim_marker = "",
    ?string $encoding = null
): string

Truncates string string to specified width, where halfwidth characters count as 1, and fullwidth characters count as 2. See » http://www.unicode.org/reports/tr11/ for details regarding East Asian character widths.

Parameter-Liste

string

The string being decoded.

start

The start position offset. Number of characters from the beginning of string (first character is 0), or if start is negative, number of characters from the end of the string.

width

The width of the desired trim. If negative width is specified, count from the end of the string.

Hinweis:
Passing negative width is deprecated as of PHP 8.3.0.

trim_marker

A string that is added to the end of string when string is truncated.

encoding

Der Parameter encoding legt die Zeichenkodierung fest. Wird er nicht übergeben, so wird die interne Zeichenkodierung genutzt.

Rückgabewerte

The truncated string. If trim_marker is set, trim_marker replaces the last chars to match the width.

Changelog

Version	Beschreibung
8.3.0	Passing a negative `width` to mb_strimwidth() is now deprecated.
8.0.0	`encoding` ist nun nullable (akzeptiert den `null`-Wert).
7.1.0	Support for negative `start`s and `width`s has been added.

Beispiele

Beispiel #1 mb_strimwidth() example

<?php
echo mb_strimwidth("Hello World", 0, 10, "...");
// output: "Hello W..."
?>

Siehe auch

mb_strwidth() - Return width of string
mb_internal_encoding() - Set/Get internal character encoding

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User Contributed Notes 2 notes

down

jamesgrimshaw2006 at gmail dot com ¶

1 year ago


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

down

dregad at NOSPAM-mantisbt dot org ¶

1 year ago


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
*/
>?

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