type.js

/**
 * toString ref.
 */

var toString = Object.prototype.toString;

/**
 * Return the type of `val`.
 *
 * @param {Mixed} val
 * @return {String}
 * @api public
 */

module.exports = function(val){
    switch (toString.call(val)) {
        case '[object Function]': return 'function';
        case '[object Date]': return 'date';
        case '[object RegExp]': return 'regexp';
        case '[object Arguments]': return 'arguments';
        case '[object Array]': return 'array';
        case '[object String]': return 'string';
    }

    if (val === null) return 'null';
    if (val === undefined) return 'undefined';
    if (val && val.nodeType === 1) return 'element';
    if (val === Object(val)) return 'object';

    return typeof val;
};