PHP htmlentities()Functions

PHP String 参考手册PHP String Reference Manual

Examples

Convert some characters to HTML entities:

<?php
$str = "<© W3CSçh°°¦§>";
echo htmlentities($str);
?>

The HTML output of the above code is as follows (view source):

<!DOCTYPE html>
<html>
<body>
&lt;&copy; W3CS&ccedil;h&deg;&deg;&brvbar;&sect;&gt;
</body>
</html>

The browser output of the above code is as follows:

<© W3CSçh°°¦§>

Run example »

Definition and Usage

The htmlentities() function converts characters to HTML entities.

Tip:To convert HTML entities back to characters, use thehtml_entity_decode()function.

Tip:Please use the get_html_translation_table()function to return the translation table used by htmlentities().


Syntax

htmlentities(string,flags,character-set,double_encode)

Parameter Description
string Required. Specifies the string to convert.
flags Optional. Specifies how to handle quotes, invalid encoding, and which document type to use.

Available quote types:

  • ENT_COMPAT - Default. Encodes double quotes only.
  • ENT_QUOTES - Encodes double and single quotes.
  • ENT_NOQUOTES - Does not encode any quotes.

Invalid encoding:

  • ENT_IGNORE - Ignores invalid encoding instead of having the function return an empty string. This should be avoided as it may have security implications.
  • ENT_SUBSTITUTE - Replaces invalid encoding with a specified character containing the Unicode replacement character U+FFFD (UTF-8) or &#FFFD;, instead of returning an empty string.
  • ENT_DISALLOWED - Replaces invalid code points in the specified document type with the Unicode replacement character U+FFFD (UTF-8) or &#FFFD;.

Additional flags specifying the document type to use:

  • ENT_HTML401 - Default. Handle code as HTML 4.01.
  • ENT_HTML5 - Handle code as HTML 5.
  • ENT_XML1 - Handle code as XML 1.
  • ENT_XHTML - Handle code as XHTML.
character-set Optional. A string specifying the character set to use.

Allowed values:

  • UTF-8 - Default. ASCII compatible multibyte 8-bit Unicode
  • ISO-8859-1 - Western European
  • ISO-8859-15 - Western European (adds the Euro sign + French and Finnish letters missing in ISO-8859-1)
  • cp866 - DOS-specific Cyrillic character set
  • cp1251 - Windows-specific Cyrillic character set
  • cp1252 - Windows-specific Western European character set
  • KOI8-R - Russian
  • BIG5 - Traditional Chinese, mainly used in Taiwan
  • GB2312 - Simplified Chinese, national standard character set
  • BIG5-HKSCS - Big5 with Hong Kong extensions
  • Shift_JIS - Japanese
  • EUC-JP - Japanese
  • MacRoman - Character set used by Mac operating systems

Notes:In versions before PHP 5.4, unrecognized character sets are ignored and replaced by ISO-8859-1. As of PHP 5.4, unrecognized character sets are ignored and replaced by UTF-8.

double_encode Optional. A boolean that specifies whether to encode existing HTML entities.
  • TRUE - Default. Will convert every entity.
  • FALSE - Will not encode existing HTML entities.

Technical Details

Return value: Returns the converted string.

Ifstringcontains invalid encoding, an empty string is returned unless the ENT_IGNORE or ENT_SUBSTITUTE flag is set.
PHP Version: 4+
Changelog: In PHP 5,character-setthe default value of the parameter was changed to UTF-8.

In PHP 5.4, added: ENT_SUBSTITUTE, ENT_DISALLOWED, ENT_HTML401, ENT_HTML5, ENT_XML1 and ENT_XHTML.

In PHP 5.3, added ENT_IGNORE.

In PHP 5.2.3, added thedouble_encodeparameter.

In PHP 4.1, added thecharacter-setparameter.


More Examples

Example 1

Convert some characters to HTML entities:

<?php
$str = "Jane & 'Tarzan'";
echo htmlentities($str, ENT_COMPAT); // Will only convert double quotes
echo "<br>";
echo htmlentities($str, ENT_QUOTES); // Converts double and single quotes
echo "<br>";
echo htmlentities($str, ENT_NOQUOTES); // Does not convert any quotes
?>

The HTML output of the above code is as follows (view source):

<!DOCTYPE html>
<html>
<body>
Jane &amp; 'Tarzan'<br>
Jane &amp; &#039;Tarzan&#039;<br>
Jane &amp; 'Tarzan'
</body>
</html>

The browser output of the above code is as follows:

Jane & 'Tarzan'
Jane & 'Tarzan'
Jane & 'Tarzan'

Run example »

Example 2

Convert some characters to HTML entities using the Western European character set:

<?php
$str = "My name is Øyvind Åsane. I'm Norwegian.";
echo htmlentities($str, ENT_QUOTES, "ISO-8859-1"); // Will only convert double quotes (not single quotes), and uses the character-set Western European
?>

The HTML output of the above code is as follows (view source):

<!DOCTYPE html>
<html>
<body>
My name is &Oslash;yvind &Aring;sane. I&#039;m Norwegian.
</body>
</html>

The browser output of the above code is as follows:

My name is Øyvind Åsane. I'm Norwegian.

Run example »


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