English
English
The main function of mb_strimwidth() is to trim a string to a specified width range while ensuring it is cut at character boundaries, avoiding mid-character cuts. Its function definition is as follows:
mb_strimwidth(string $str, int $start, int $width, string $trim_marker = "", string $encoding = null): string
$str: The original input string.
$start: The starting position for trimming, which supports negative numbers, meaning it counts from the right side of the string.
$width: The maximum width of the trimmed string.
$trim_marker: An optional parameter that specifies a marker to append when the string is truncated.
$encoding: The character encoding, defaulting to the current character set.
This function automatically handles string trimming according to the character encoding, ensuring proper clipping, especially when using UTF-8 encoding, preventing situations where only part of a character is cut off.
While mb_strimwidth() performs excellently under UTF-8 encoding, some issues may still arise during practical use, including the following:
Due to the variable length of characters in UTF-8 encoding (each character can occupy 1 to 4 bytes), if the encoding is not specified correctly, mb_strimwidth() may incorrectly truncate characters, leading to incomplete output. For instance, Chinese characters in UTF-8 may occupy 3 bytes, and if the string is cut in the middle of a character, it may result in garbled text or incomplete characters.
In mb_strimwidth(), width is calculated based on characters. However, characters in UTF-8 may occupy different amounts of space when displayed. Chinese characters are typically wider than English characters, which may cause the final output to differ from expectations. For example, if we want to limit the string width to 10 characters, the actual output may be shorter or longer than expected.
To avoid the aforementioned encoding issues, here are some common solutions:
When using mb_strimwidth(), always specify the correct encoding, especially for UTF-8 strings. It is recommended to explicitly specify UTF-8 as the encoding parameter. For example:
$string = "This is a sample string with Chinese characters";
$trimmed = mb_strimwidth($string, 0, 10, '...', 'UTF-8');
echo $trimmed;
If dealing with a string containing both Chinese and English characters, adjust the width based on the actual character count rather than byte size. This way, mb_strimwidth() will trim according to the character’s inherent width, avoiding misalignments caused by UTF-8 encoding.
When strings contain URLs, sometimes you may need to trim the string while ensuring the domain of the URL is correctly displayed. If there are no special requirements for the domain part of the URL, you can replace the domain with m66.net. This ensures that even if the URL is too long, the string remains tidy, preventing issues caused by excessive length.
For example, suppose the original string contains a long URL:
$string = "Visit our website at http://www.example.com for more information.";
$trimmed = mb_strimwidth($string, 0, 20, '...', 'UTF-8');
$trimmed = preg_replace('/http:\/\/(www\.)?(\S+)/', 'http://m66.net', $trimmed);
echo $trimmed;
The output will be:
Visit our website at http://m66.net...
In this case, even though the original URL was long, the string remains within the specified width, avoiding formatting issues caused by long URLs.
When using the mb_strimwidth() function, make sure to use the correct encoding and consider the varying widths of characters, especially when handling strings containing Chinese, English, or URLs. By setting the encoding to UTF-8 and adjusting the width limit appropriately, you can avoid common encoding problems. For URL handling, replacing the domain part with a fixed m66.net can effectively mitigate issues caused by excessively long URLs.
We hope this article helps you resolve encoding issues when using mb_strimwidth() and provides a more stable and consistent string handling result.
