(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)
mb_strimwidth — Get truncated string with specified width
$string,$start,$width,$trim_marker = "",$encoding = null
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.
stringThe string being decoded.
startThe 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.
widthThe width of the desired trim. If negative width is specified, count from the end of the string.
Note:
Passing negative width is deprecated as of PHP 8.3.0.
trim_markerA string that is added to the end of string when string is truncated.
encodingThe encoding
parameter is the character encoding. If it is omitted or null , the internal character
encoding value will be used.
The truncated string . If trim_marker is set,
trim_marker replaces the last chars to match the width.
| Version | Description |
|---|---|
| 8.3.0 |
Passing a negative width to
mb_strimwidth() is now deprecated.
|
| 8.0.0 |
encoding is nullable now.
|
| 7.1.0 |
Support for negative starts and widths has been added.
|
Example #1 mb_strimwidth() example
<?php
echo mb_strimwidth("Hello World", 0, 10, "...");
// output: "Hello W..."
?>
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