URL-encoding in JavaScript
JavaScript FAQ |
JavaScript Strings and RegExp FAQ
|
Question: How do I convert a string to URL-encoding?
Answer:
You can convert any string to a URL-encoded string (suitable for transmission as a query string or, generally speaking, as part of a URL)
using the JavaScript functions escape, encodeURI and encodeURIComponent.
Below is a detailed discussion of these functions.
escape In all browsers that support JavaScript, you can use the escape function.
This function works as follows:
digits, Latin letters and the characters + - * / . _ @
remain unchanged; all other characters in the original string
are replaced by escape-sequences %XX, where
XX is the ASCII code of the original character.
Example:
escape("It's me!") // result: It%27s%20me%21
For Unicode input strings,
the function escape has a more complex behavior.
If the input is a Unicode string, then non-ASCII Unicode characters
will be converted to the Unicode escape-sequences %uXXXX. For example,
escape will encode the capital Cyrillic letter A as %u0410.
To decode strings encoded with escape,
use the JavaScript function unescape.
encodeURI and encodeURIComponent
In addition to escape, modern browsers support two more functions for URL-encoding:
encodeURI and encodeURIComponent. These functions are similar to
escape, except that they leave intact some characters that escape
encodes (e.g. apostrophe, tilde, parentheses);
moreover, encodeURIComponent encodes some characters (+ / @) that escape leaves intact.
Unlike escape, the encodeURI and encodeURIComponent functions
do not produce %uXXXX for Unicode input; instead, they produce %XX%XX or %XX%XX%XX.
For example, encodeURI and encodeURIComponent
will encode the capital Cyrillic letter A as %D0%90, and the euro sign (€) as %E2%82%AC.
To decode strings encoded with encodeURI and encodeURIComponent,
use the JavaScript functions decodeURI and decodeURIComponent, respectively.
The following tables illustrate the differences between
escape, encodeURI, and encodeURIComponent.