var DefaultTypes = {

    'undefined': true,

    'boolean': true,

    'number': true,

    'string': true,

    'function': true

};

​

function typeOf(type) {

    switch (Object.prototype.toString.call(type)) {

        case '[object Array]':

            return 'array';

        case '[object Null]':

            return 'null';

        case '[object Object]':

            return 'object';

        default:

            if (typeof(type) in DefaultTypes) {

                return typeof(type);

            } else if (typeof(type) === 'object' && type.length >= 0 && type[0]) {

                return 'array-like';

            }

    }

}

​

console.log(typeOf(document.getElementsByTagName('div')));