How to escape dots in php regular expressions

In PHP, you can use the "preg_quote()" function to escape dots. This function is used to escape regular expression characters. You can add a backslash before the characters in the regular expression syntax. , the syntax is "preg_quote('.', '/')".

The operating environment of this article: Windows 10 system, PHP version 7.1, Dell G3 computer.

How to escape dots in php regular expressions

The preg_quote function is used to escape regular expression characters.

Syntax

string preg_quote ( string $str [, string $delimiter = NULL ] )

preg_quote() requires the parameter str and adds a backslash before each character in the regular expression syntax. This is typically used when you have some runtime strings that need to be matched as regular expressions.

Regular expression special characters are: . \ * ? [ ^ ] $ ( ) { } = ! | : -

Parameter description:

$ str: input string.

$delimiter: If the optional parameter delimiter is specified, it will also be escaped. This is typically used to escape delimiters used by the PCRE function. / is the most common delimiter.

Return value

Returns the escaped string.

Examples are as follows:

<?php
$keywords = &#39;afweaef.afdafaw&#39;;
$keywords1 = preg_quote(&#39;.&#39;, &#39;/&#39;);
$keywords = preg_quote($keywords, &#39;/&#39;);
echo $keywords . "<br>"; 
echo $keywords1; 
?>

Output results:

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