URL EncodeDecode

Remarks

The regular expression used in the Decode URL examples was taken from RFC 2396, Appendix B: Parsing a URI Reference with a Regular Expression; for posterity, here’s a quote:

The following line is the regular expression for breaking-down a URI reference into its components.

^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
 12            3  4          5       6  7        8 9

The numbers in the second line above are only to assist readability; > they indicate the reference points for each subexpression (i.e., each > paired parenthesis). We refer to the value matched for subexpression > as $. For example, matching the above expression to

http://www.ics.uci.edu/pub/ietf/uri/#Related

results in the following subexpression matches:

$1 = http:
$2 = http
$3 = //www.ics.uci.edu
$4 = www.ics.uci.edu
$5 = /pub/ietf/uri/
$6 = <undefined>
$7 = <undefined>
$8 = #Related
$9 = Related