String Functions
PHP Manual

htmlentities

(PHP 4, PHP 5)

htmlentitiesConvert all applicable characters to HTML entities

Description

string htmlentities ( string $string [, int $flags = ENT_COMPAT | ENT_HTML401 [, string $charset [, bool $double_encode = true ]]] )

This function is identical to htmlspecialchars() in all ways, except with htmlentities(), all characters which have HTML character entity equivalents are translated into these entities.

If you're wanting to decode instead (the reverse) you can use html_entity_decode().

Parameters

string

The input string.

flags

A bitmask of one or more of the following flags, which specify how to handle quotes, invalid code unit sequences and the used document type. The default is ENT_COMPAT | ENT_HTML401.

Available flags constants
Constant Name Description
ENT_COMPAT Will convert double-quotes and leave single-quotes alone.
ENT_QUOTES Will convert both double and single quotes.
ENT_NOQUOTES Will leave both double and single quotes unconverted.
ENT_IGNORE Silently discard invalid code unit sequences instead of returning an empty string. This is provided for backwards compatibility; avoid using it as it may have security implications.
ENT_SUBSTITUTE Replace invalid code unit sequences with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise) instead of returning an empty string.
ENT_DISALLOWED Replace code unit sequences, which are invalid in the specified document type, with a Unicode Replacement Character U+FFFD (UTF-8) or &#FFFD; (otherwise).
ENT_HTML401 Handle code as HTML 4.01.
ENT_XML1 Handle code as XML 1.
ENT_XHTML Handle code as XHTML.
ENT_HTML5 Handle code as HTML 5.

charset

Like htmlspecialchars(), it takes an optional third argument charset which defines character set used in conversion. Presently, the ISO-8859-1 character set is used as the default. However, this default is very likely to change in future versions of PHP; the programmer is highly encouraged to specify a value.

Following character sets are supported in PHP 4.3.0 and later.

Supported charsets
Charset Aliases Description
ISO-8859-1 ISO8859-1 Western European, Latin-1
ISO-8859-15 ISO8859-15 Western European, Latin-9. Adds the Euro sign, French and Finnish letters missing in Latin-1 (ISO-8859-1).
UTF-8   ASCII compatible multi-byte 8-bit Unicode.
cp866 ibm866, 866 DOS-specific Cyrillic charset. This charset is supported in 4.3.2.
cp1251 Windows-1251, win-1251, 1251 Windows-specific Cyrillic charset. This charset is supported in 4.3.2.
cp1252 Windows-1252, 1252 Windows specific charset for Western European.
KOI8-R koi8-ru, koi8r Russian. This charset is supported in 4.3.2.
BIG5 950 Traditional Chinese, mainly used in Taiwan.
GB2312 936 Simplified Chinese, national standard character set.
BIG5-HKSCS   Big5 with Hong Kong extensions, Traditional Chinese.
Shift_JIS SJIS, 932 Japanese
EUC-JP EUCJP Japanese
''   An empty string activates detection from script encoding (Zend multibyte), default_charset and current locale (see nl_langinfo() and setlocale()), in this order. Not recommended.

Note: Any other character sets are not recognized. The default encoding will be used instead and a warning will be emitted.

double_encode

When double_encode is turned off PHP will not encode existing html entities. The default is to convert everything.

Return Values

Returns the encoded string.

Changelog

Version Description
5.4.0 The constants ENT_SUBSTITUTE, ENT_DISALLOWED, ENT_HTML401, ENT_XML1, ENT_XHTML and ENT_HTML5 were added.
5.3.0 The constant ENT_IGNORE was added.
5.2.3 The double_encode parameter was added.
4.1.0 The charset parameter was added.
4.0.3 The flags parameter was added.

Examples

Example #1 A htmlentities() example

<?php
$str 
"A 'quote' is <b>bold</b>";

// Outputs: A 'quote' is &lt;b&gt;bold&lt;/b&gt;
echo htmlentities($str);

// Outputs: A &#039;quote&#039; is &lt;b&gt;bold&lt;/b&gt;
echo htmlentities($strENT_QUOTES);
?>

Example #2 Usage of ENT_IGNORE

<?php
$str 
"\x8F!!!";

// Outputs an empty string
echo htmlentities($strENT_QUOTES"UTF-8");

// Outputs "!!!"
echo htmlentities($strENT_QUOTES ENT_IGNORE"UTF-8");
?>

See Also


String Functions
PHP Manual