140byt.es -- Fast and recursive object extend/clon

README.md

140byt.es

A tweet-sized, fork-to-play, community-curated collection of JavaScript.

How to play

1. Click the button above to fork this gist.
2. Modify all the files to according to the rules below.
3. Save your entry and tweet it up!

Keep in mind that thanks to the awesome sensibilities of the GitHub team, gists are just repos. So feel free to clone yours and work locally for a more comfortable environment, and to allow commit messages.

Rules

All entries must exist in an index.js file, whose contents are

1. an assignable, valid Javascript expression that
2. contains no more than 140 bytes, and
3. does not leak to the global scope.

All entries must also be licensed under the WTFPL or equally permissive license.

For more information

See the 140byt.es site for a showcase of entries (built itself using 140-byte entries!), and follow @140bytes on Twitter.

To learn about byte-saving hacks for your own code, or to contribute what you've learned, head to the wiki.

140byt.es is brought to you by Jed Schmidt, with help from Alex Kloss. It was inspired by work from Thomas Fuchs and Dustin Diaz.

annotated.js

//Clone is the object to copy the the attributes of obj to.
function x(clone, obj) {

   //iterate over the attributes of obj
   for(var i in obj)    
 
     /* copy the attribute.  If the attribute is a [] or {}, create an object of the
      same type and copy the values of the target to it. */

     clone[i] = (typeof obj[i] == "object") ? x(obj[i].constructor(), obj[i]) : obj[i];

   return clone; // return the clone
}

index.js

function extend2(a,b){for(var c in b)a[c]="object"==typeof b[c]?extend2(b[c].constructor(),b[c]):b[c];return a}

LICENSE.txt

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
                    Version 2, December 2004

 Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE>

 Everyone is permitted to copy and distribute verbatim or modified
 copies of this license document, and changing it is allowed as long
 as the name is changed.

            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

  0. You just DO WHAT THE FUCK YOU WANT TO.

package.json

{
  "name": "extend2",

  "description": "The fastest way to deep clone/extend an object.  It is very small.",

  "keywords": [
    "object",
    "clone",
    "extend",
    "deep",
    "fast"
  ]
}