ZzJavaScript encode and escape functions

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JavaScript encode and escape functions

The encodeURI, encodeURIComponent and escape functions convert special characters in URLs and other URIs by percent encoding the special characters.

JavaScript: encodeURI functionThe JavaScript encodeURI function is used to encode an entire unencoded URI, such as http://authority@www.ExampleOnly.com/my path/my filename.ext?width=100%&my key=my value#fragment-id. It is most useful when the entire URI is hard-coded in the JavaScript code, so that escaping of special characters within any component is already done manually.

• encodes all characters that should never be included in a valid URI
• also encodes any percent signs, which is used to encode the unsafe characters
• leaves intact the special characters #& ./:=?@ that act as delimiters within a URI along with $; and all other characters not encoded by encodeURIComponent
• uses percent escape encoding of individual UTF-8 octets for non-ASCII characters

JavaScript: encodeURIComponent functionThe JavaScript encodeURIComponent function can be used to encode individual components of a URI such as http, authority, www.ExampleOnly.com, my path, my filename.ext, width, 100%, my key, my value and fragment-idfrom the example used for encodeURI above. This is the function that should be used when the URI is being constructed from variables containing individual components of the URI.

• encodes the special characters #$& ,/:;=?@ within a component, in addition to those encoded by the encodeURI function, so they won't be misinterpreted as URI delimiters
• leaves intact the alphanumeric characters and special characters !'()*-._~, which are considered "safe" by RFC 1738, but does encode the characters $ , anyway
• uses percent escape encoding of individual UTF-8 octets for non-ASCII characters

JavaScript: escape function

• The JavaScript escape function should be avoided but may be seen in older code that encodes a space as a plus sign (+) or that was designed to be compatible with older browsers
• should not be used for text that may contain non-ASCII characters because Unicode characters are converted into a non-standard format as <strong style="border: 0px; padding: 0px;">%u</strong><em style="border: 0px; padding: 0px;">nnnn</em> rather than using UTF-8 percent escape codes

JavaScript percent-encoding functions

In all cases, the resulting URI still needs to be converted to valid HTML, by encoding quotes within attributes, ampersands, etc. using HTML character codes.

(space)	%20	%20	%20	%20
!	!	!	!	%21
"	%22	%22	%22	%22
#	#	#	%23	%23
$	$	$	%24	%24
%	%25	%25	%25	%25
&	&	&	%26	%26
'	'	'	'	%27
(	(	(	(	%28
)	)	)	)	%29
*	*	*	*	*
(space)	%20	%20	%20	%20
,	,	,	%2C	%2C
-	-	-	-	-
.	.	.	.	.
/	/	/	%2F	/
:	:	:	%3A	%3A
;	;	;	%3B	%3B
<	%3C	%3C	%3C	%3C
=	=	=	%3D	%3D
>	%3E	%3E	%3E	%3E
?	?	?	%3F	%3F
@	@	@	%40	@
[	%5B	%5B	%5B	%5B
\	%5C	%5C	%5C	%5C
]	%5D	%5D	%5D	%5D
^	%5E	%5E	%5E	%5E
_	_	_	_	_
`	%60	%60	%60	%60
{	%7B	%7B	%7B	%7B
|	%7C	%7C	%7C	%7C
}	%7D	%7D	%7D	%7D
~	~	~	~	%7E
©	%C2%A9	%C2%A9	%C2%A9	%A9
®	%C2%AE	%C2%AE	%C2%AE	%AE
—	%E2%80%94	%E2%80%94	%E2%80%94	%u2014
™	%E2%84%A2	%E2%84%A2	%E2%84%A2	%u2122