How to remove utf8 symbols in php

php method to remove utf8 symbols: 1. Create a PHP sample file; 2. Use "preg_replace('/[x00-x08x10x0Bx0Cx0E-x19x7F]'." regular method to match illegal utf8 symbols and delete them.

The operating environment of this tutorial: Windows 7 system, PHP version 8.1, Dell G3 computer.

php How to remove utf8 symbols ?

PHP Delete illegal UTF-8 characters

The code is as follows:

//reject overly long 2 byte sequences, as well as characters above U+10000 and replace with ?
$some_string = preg_replace('/[x00-x08x10x0Bx0Cx0E-x19x7F]'.
 '|[x00-x7F][x80-xBF]+'.
 '|([xC0xC1]|[xF0-xFF])[x80-xBF]*'.
 '|[xC2-xDF]((?![x80-xBF])|[x80-xBF]{2,})'.
 '|[xE0-xEF](([x80-xBF](?![x80-xBF]))|(?![x80-xBF]{2})|[x80-xBF]{3,})/S',
 '?', $some_string );
//reject overly long 3 byte sequences and UTF-16 surrogates and replace with ?
$some_string = preg_replace('/xE0[x80-x9F][x80-xBF]'.
 '|xED[xA0-xBF][x80-xBF]/S','?', $some_string );

preg_replace function performs a regular expression search and replace.

Syntax

mixed preg_replace (mixed $pattern, mixed $replacement, mixed $subject [, int $limit = -1 [, int &$count ]] )

Search for matching pattern in subject part, replace with replacement.

Parameter description:

• $pattern: The pattern to be searched, which can be a string or a string array.

• $replacement: The string or string array used for replacement.

• $subject: The target string or string array to search for replacement.

• $limit: Optional, the maximum number of substitutions for each subject string per pattern. The default is -1 (no limit).

• $count: Optional, the number of times the replacement is performed.

Return value

If subject is an array, preg_replace() returns an array , otherwise a string is returned.

If a match is found, the replaced subject is returned, otherwise the unchanged subject is returned. If an error occurs, NULL is returned.

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