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PHP htmlspecialchars() Function Usage and Example

　　 The htmlspecialchars() function is used to convert special characters to HTML entities.

Syntax

string htmlspecialchars(string $string[, int $flags = ENT_COMPAT | ENT_HTML401　[, string $encoding = ini_get("default_charset")[, bool $double_encode = true]])

Definition and usage

Used to convert special characters to HTML entities

Return value

It returns the converted string (string).
If the specified encoding 'encoding' contains invalid code unit sequences in 'string', and no ENT_IGNORE or ENT_SUBSTITUTE flags are set, an empty string will be returned.

The predefined characters are:

& (ampersand) becomes &
" (double quote) becomes "
' (single quote) becomes '
< (less than) becomes <
> (greater than) becomes >

Note:To convert special HTML entities back to characters, use htmlspecialchars_decode() Function.

Parameter

Serial number	Parameters and descriptions
1	string Required. It contains information about the input string
2	flags Optional. Specify how to handle quotes, invalid encodings, and which document type to use. Available quote types: ENT_COMPAT - Default. Only encode double quotes. ENT_QUOTES - Encode double quotes and single quotes. ENT_NOQUOTES - Do not encode any quotes. Invalid encoding: ENT_IGNORE - Ignore invalid encodings instead of returning an empty string from the function. It should be avoided as it may affect security. ENT_SUBSTITUTE - Replace invalid encoding with a specified Unicode replacement character U+FFFD(UTF-8) or &#FFFD; characters, rather than returning an empty string. ENT_DISALLOWED - Replace invalid code points in the specified document type with Unicode replacement character U+FFFD(UTF-8) or &#FFFD;. Specify additional flags for the document type used. ENT_HTML401 - Default. As HTML 4.01 Handling code. ENT_HTML5 - As HTML 5 Handling code. ENT_XML1 - As XML 1 Handling code. ENT_XHTML - As XHTML handling code.
3	encoding It is an optional parameter that defines the encoding used when converting characters. Allowed values: UTF-8 - Default. ASCII compatible multi-byte 8 Bit Unicode ISO-8859-1 - Western European ISO-8859-15 - Western European (including Euro symbol + ISO-8859-1 French and Finnish letters lost in Chinese cp866 - DOS专用 Cyrillic character set cp1251 - Windows专用 Cyrillic character set cp1252 - Windows专用 Western European character set KOI8-R - Russian BIG5 - Traditional Chinese, mainly used in Taiwan GB2312 - Simplified Chinese, National Character Set BIG5-HKSCS - Big5 with Hong Kong extension5 Shift_JIS - Japanese EUC-JP - Japanese MacRoman - Character set used by the Mac operating system Note:In PHP 5.4 earlier versions, unrecognized character sets are ignored and replaced by ISO-8859-1 Replace with. Since PHP 5.4 Starting with PHP-8 Replace with.
4	double_encode A boolean value that specifies whether existing HTML entities should be encoded. TRUE - Default. Converts each entity. FALSE - It will not encode existing HTML entities.

Online Example

Try the following example, converting predefined characters to HTML entities:

Example

<?php
　　　//Convert predefined characters to HTML entities, encoding double quotes and single quotes
　　　$input = htmlspecialchars("<a href='https://www.oldtoolbag.com'>w3codebox</a>"
　　　echo $input;
?>

Test and see‹/›

Output Result-

<a href='https://www.oldtoolbag.com'>w3codebox</a>

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