mb_strimwidth

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

mb_strimwidth — 获取按指定宽度截断的字符串

说明

mb_strimwidth ( string $str , int $start , int $width [, string $trimmarker = "" [, string $encoding = mb_internal_encoding() ]] ) : string

按 width 将字符串 str 截短。

参数

str: 要截短的 string。
start: 开始位置的偏移。从这些字符数开始的截取字符串。（默认是 0 个字符）如果 start 是负数，就是字符串结尾处的字符数。
width: 所需修剪的宽度。负数的宽度是从字符串结尾处统计的。
trimmarker: 当字符串被截短的时候，将此字符串添加到截短后的末尾。
encoding: encoding 参数为字符编码。如果省略，则使用内部字符编码。

返回值

截短后的 string。如果设置了 trimmarker，还将结尾处的字符替换为 trimmarker ，并符合 width 的宽度。

更新日志

版本	说明
7.1.0	支持负数的 `start` 和 `width`。

范例

Example #1 mb_strimwidth() 例子


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

参见

mb_strwidth() - 返回字符串的宽度
mb_internal_encoding() - 设置/获取内部字符编码

User Contributed Notes

felixstar4 at gmail dot com 11-Apr-2018 05:53


Note that the trimmarker removes characters from the end of the string to trim, so



$hello = 'Lorem ipsum dolor sit amet, lorem ipsum';

$trimmarker = '......................';

echo mb_strimwidth($hello, 0, 20,  $trimmarker);

 

will only add the values of the trim marker, as the character number of $trimmarker is longer than the specified value to trim to, so it will return: 

 ......................

It is therefore better to use this: 

mb_strimwidth($hello, 0, 20). $trimmarker;

as the trimmarker won't remove characters of the string in order to make space for itself. It will return:

Lorem ipsum dolor si......................

Rich Mehta 22-May-2014 02:58


I had a problem (as in another comment) with a space being between the trailing dots and the subject being truncated. Here's how I fixed it:



<?php str_replace( " .", ".", mb_strimwidth( $subject, 0, 30, "..." ) ); ?>

CBieser 26-Aug-2008 12:50


<?php


function strimwidthCenter( $value, $length = 40 ) {


    $valueEncoding = mb_detect_encoding( $value, 'auto', true );


    if ( $length >= mb_strwidth( $value, $valueEncoding ) ) {


        return $value;


    }


    $limited = '';


    $firstWidth = ceil( $length/2 );


    $secondStart = mb_strwidth( $value, $valueEncoding ) - ( $length - $firstWidth );


    $secondWidth = $length - $firstWidth +1;


    $limited = mb_strimwidth( $value, 0, $firstWidth, '...', $valueEncoding ) . mb_substr( $value, $secondStart, $secondWidth, $valueEncoding );


    return $limited;


}


?>

josiah dot ritchie at gmail dot com 13-Sep-2007 11:48


While having the option to append a string to the end is nice, you can run into the problem of having a space between the append if the width is truncated after a space. I find something like this to be more attractive in the output, although messy in the code.



rtrim(mb_strimwidth($string, 0, 24))."..."