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.
Like htmlspecialchars(), the optional second quote_style parameter lets you define what will be done with 'single' and "double" quotes. It takes on one of three constants with the default being ENT_COMPAT:
Table 1. Available quote_style 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. |
Support for the optional quote parameter was added in PHP 4.0.3.
Like htmlspecialchars(), it takes an optional third argument which defines character set used in conversion. Support for this argument was added in PHP 4.1.0. Presently, the ISO-8859-1 character set is used as the default.
If you're wanting to decode instead (the reverse) you can use html_entity_decode().
See also html_entity_decode(), get_html_translation_table(), htmlspecialchars(), nl2br(), and urlencode().