Selector function in 140byt.es

annotated.js

function(
    i, //the selector parameter
    f, //placeholder
    s //placeholder
) {
    f = i[0];                         //extract the first character of the selector
    s = i.substr(1);                  //extract the remaining part of the selector after a possible '#' or  '.'
    return document['getElement' + ({ //call document.getElement.... we'll complete the method name later with this map which has '#' and '.' as it's keys
        '#': 'ById',                  //this handles ID selectors with .getElementById()
        '.': 'sByClassName'           //class selectors are handled with .getElementsByClassName()
    }[f] || 'sByTagName')]({          //Everything else is handled with .getElementsByTagName()
        '#': s,                       
        '.': s
    }[f] || i)                        //we call the method either with the complete selector i (for tag names) or with the shortened one s
}

example.js

//suppose, the function has been assinged to "$":

$('#foo'); //returns one DOM element with the ID "foo"
$('.bar'); //returns an array of DOM elements with the class "bar"
$(div);    //returns an array of all <div> elements

index.js

function(i,f,s){f=i[0];s=i.substr(1);return document['getElement'+({'#':'ById','.':'sByClassName'}[f]||'sByTagName')]({'#':s,'.':s}[f]||i)}

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": "Selector140",

  "description": "Accepts a single ID, class or tag name selector and return the matching DOM elements",

  "keywords": [
    "140bytes",
    "DOM",
    "selector",
    "matching"
  ]
}