Certain characters have special significance in HTML,
and should be represented by HTML entities if they are to
preserve their meanings. This function returns a string with
some of these conversions made; the translations made are
those most useful for everyday web programming. If you
require all HTML character entities to be translated, use
htmlentities() instead.
This function is useful in preventing user-supplied text
from containing HTML markup, such as in a message board or
guest book application. The optional second argument,
quote_style, tells the function what to do with single and
double quote characters. The default mode, ENT_COMPAT, is the
backwards compatible mode which only translates the
double-quote character and leaves the single-quote
untranslated. If ENT_QUOTES is set, both single and double
quotes are translated and if ENT_NOQUOTES is set neither
single nor double quotes are translated.
The translations performed are:
' ' (ampersand) becomes ' amp;'
'"' (double quote) becomes ' quot;' when
ENT_NOQUOTES is not set.
''' (single quote) becomes ' #039;' only when
ENT_QUOTES is set.
' ' (less than) becomes ' lt;'
' ' (greater than) becomes ' gt;'
Note that this function does not translate anything
beyond what is listed above. For full entity translation, see
htmlentities(). Support for the optional second
argument was added in PHP 3.0.17 and PHP 4.0.3.
The third argument defines character set used in
conversion. The default character set is ISO-8859-1. Support
for this third argument was added in PHP 4.1.0.
See also get_html_translation_table(),
htmlentities() and nl2br().