JavaScript function to serve as a replacement for native typeof that returns more useful values. Example usage page at http://lucassmith.name/pub/typeof.html

typeof.js

var _toS = Object.prototype.toString,
    _types = {
        'undefined'         : 'undefined',
        'number'            : 'number',
        'boolean'           : 'boolean',
        'string'            : 'string',
        '[object Function]' : 'function',
        '[object RegExp]'   : 'regexp',
        '[object Array]'    : 'array',
        '[object Date]'     : 'date',
        '[object Error]'    : 'error'
    };

// Function name can't be can't be typeof or typeOf because Safari barfs on
// the reserved word use.  Non-IE browsers report the browser object classes
// in the toString e.g. '[object HTMLDivElement]', but IE always returns
// '[object Object]' for DOM objects and methods because they are COM objects
function type(o) {
    return  _types[typeof o] || _types[_toS.call(o)] || (o?'object':'null');
}