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Encoding all the special characters in Javascript

I have to encode the string that I receive here and pass it as a URL parameter so I don't believe I can pass either / or a paranthesis ( so considering I have the following string
KEY WEST / Florida(FL)
I am trying the following
encodeURIComponent("KEY WEST / Florida(FL)")
"KEY%20WEST%20%2F%20Florida(FL)"
escape("KEY WEST / Florida(FL)")
"KEY%20WEST%20/%20Florida%28FL%29"
Neither of them are encoding the string which I can decode later in my code as the first one is keeping the () and the second one is keeping the /
How do I do this in one shot and at a later time decode it when needed?
Also it seems like escape() has been deprecated so which way to do the encoding is preferred?

For URL encoding, encodeURI and encodeURIComponent functions should be used.
encodeURI encodes only special characters, while encodeURIComponent also encodes characters that have a meaning in the URL, so it is used to encode query strings, for example.
Parentheses are (as explained here), however, allowed anywhere in the URL without encoding them, that's why encodeURIComponent leaves them as-is.
The escape function can be considered deprecated, and although it officially isn't, it should be avoided.
so which way to do the encoding is preferred?
For entire URLs, encodeURI
For URL parts, e.g. query string of fragment, encodeURIComponent
Also see When are you supposed to use escape instead of encodeURI / encodeURIComponent?

What encoding type is used on this string (JavaScript)

I need to parse URLs from javascript source code using a different langauge(i.e. PHP and Java). The issue is that I don't know what kind of encoding is used on certain URLs(See below). Is there a standard(i.e. RFC, specifications) for this kind of encoding that I can use to implement it in the language I need? Initially I thought it simply backslashes the forward slashes but it seems is more than that as we have escaped characters such \x3d...
var _F_jsUrl = 'https:\/\/www.example.com\/accounts\/static\/_\/js\/k\x3dgaia.gaiafe_glif.en.nnMHsIffkD4.O\/m\x3dglifb,identifier,unknownerror\/am\x3dggIgAAAAAAEKBCEImA2CYiCxoQo\/rt\x3dj\/d\x3d1\/rs\x3dABkqax3Fc8CWFtgWOYXlvHJI_bE3oVSwgA';

Best way to encode special chars in url

What is the best way to encode special characters in a url? Let's say I pass an variable from javascript to a php script that way:
http://example.com/my sp3c!al var!a$le
What is the best way to encode that special characters (like whitespace, !, $, /, \ etc.)? Is there a method in javascript to encode it with a corresponding function in php to decode it there?

You need to make use of encodeURIComponent(yourvar);

You can do it in three ways
encodeURI(yourvar)
output http://example.com/my%20sp3c!al%20var!a$le
amd
encodeURIComponent(yourvar)
output http%3A%2F%2Fexample.com%2Fmy%20sp3c!al%20var!a%24le
escape()
output http%3A//example.com/my%20sp3c%21al%20var%21a%24le
using escape is not recomended because it is deprecated since ECMAScript v3.
functions is for JavaScript escaping, not HTTP.

javascript query string encoding

why does encodeURI and encodeURIComponent encode spaces as hex values, but then I see other encodings using the plus sign? there's something i'm obviously missing.
thanks!

IIRC + is a form encoded , while %20 is a standard URI encoding.
They are interchangeable, so don't worry about which one you use.

"+" is allowed as a substitute for spaces, however there are lots of other special characters that need escaping as hex values (in the form %nn). Presumably the authors of encodeURI and encodeURIComponent decided to use hex values for everything including space, since it made their code simpler and they didn't think the extra two characters for each space in a uri was really that important.

Look here for a discussion of the differences between escape, encodeURI, and encodeURIComponent, with interactive examples for all three of them:
http://xkr.us/articles/javascript/encode-compare/
To summarize:
The escape() method does not encode
the + character which is interpreted
as a space on the server side as well
as generated by forms with spaces in
their fields. Due to this shortcoming
and the fact that this function fails
to handle non-ASCII characters
correctly, you should avoid use of
escape() whenever possible. The
best alternative is usually
encodeURIComponent().
escape() will not encode: #*/+
Use of the encodeURI() method is a
bit more specialized than escape()
in that it encodes for
URIs
as opposed to the querystring, which
is part of a URL. Use this method when
you need to encode a string to be used
for any resource that uses URIs and
needs certain characters to remain
un-encoded. Note that this method does
not encode the ' character, as it is a
valid character within URIs.
encodeURI() will not encode:
~!##$&*()=:/,;?+'
Lastly, the encodeURIComponent()
method should be used in most cases
when encoding a single component of a
URI. This method will encode certain
chars that would normally be
recognized as special chars for URIs
so that many components may be
included. Note that this method does
not encode the ' character, as it is a
valid character within URIs.
encodeURIComponent() will not
encode: ~!*()'

Why aren't double quotes and backslashes allowed in strings in the JSON standard?

If I run this in a JavaScript console in Chrome or Firebug, it works fine.
JSON.parse('"\u0027"') // Escaped single-quote
But if I run either of these 2 lines in a Javascript console, it throws an error.
JSON.parse('"\u0022"') // Escaped double-quote
JSON.parse('"\u005C"') // Escaped backslash
RFC 4627 section 2.5 seems to imply that \ and " are allowed characters as long as they're properly escaped. The 2 browsers I've tried this in don't seem to allow it, however. Is there something I'm doing wrong here or are they really not allowed in strings? I've also tried using \" and \\ in place of \u0022 and \u005C respectively.
I feel like I'm just doing something very wrong, because I find it hard to believe that JSON would not allow these characters in strings, especially since the specification doesn't seem to mention anything that I could find saying they're not allowed.

You need to quote the backslash!
that which we call a rose
By any other name would smell as sweet
A double quote is a double quote, no matter how you express it in the string constant. If you put a backslash before your \u expression within the constant, then the effect is that of a backslash-quoted double-quote, which is in fact what you've got.
The most interesting thing about your question is that it helps me realize that every JavaScript string parser I've ever written is wrong.

JavaScript is interpreting the Unicode escape sequences before they get to the JSON parser. This poses a problem:
'"\u0027"' unquoted the first time (by JavaScript): "'" The second time (by the JSON parser) as valid JSON representing the string: '
'"\u0022"' unquoted the first time (by JavaScript): """ The JSON parser sees this unquoted version """ as invalid JSON (does not expect the last quotation mark).
'"\u005C"' unquoted the first time (by JavaScript): "\" The JSON parser also sees this unquoted version "\" as invalid JSON (second quotation mark is backslash-escaped and so does not terminate the string).
The fix for this is to escape the escape sequence, as \\u.... In reality, however, you would probably just not use the JSON parser. Used in the correct context (ensured by wrapping it within parentheses, all JSON is valid JavaScript.

You are not escaping the backslash and the double-quote, as \u00xx is being interpreted by the javascript parser.
JSON.parse('"\\\u0022"')
JSON.parse('"\\\""')
and
JSON.parse('"\\\u005C"')
JSON.parse('"\\\\"')
work as expected.