urlencode — URL-encodes string
string urlencode ( string $str )
This function is convenient when encoding a string to be used in a query part of a URL, as a convenient way to pass variables to the next page.
The string to be encoded.
urldecode — Decodes URL-encoded string
string urldecode ( string $str )
Decodes any %## encoding in the given string. Plus symbols ('+') are decoded to a space character.
The string to be decoded.
htmlentities — Convert all applicable characters to HTML entities
string htmlentities ( string $string [, int $flags = ENT_COMPAT [, 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.
Available flags constants
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. Added in PHP 5.3.0. This is provided for backwards compatibility; avoid using it as it may have security implications.
string htmlspecialchars ( string $string [, int $flags = ENT_COMPAT [, string $charset [, bool $double_encode = true ]]] )
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 translations performed are:
- '&' (ampersand) becomes '&'
- '"' (double quote) becomes '"' when ENT_NOQUOTES is not set.
- ''' (single quote) becomes ''' only when ENT_QUOTES is set.
- '<' (less than) becomes '<'
- '>' (greater than) becomes '>'
