//ВОТ ТАК РАБОТАЕТ:
function getType(f) {
        function TypeWrapper(arg) {
            var type = {}.toString.call(arg).slice(8, -1);
            return f.call(this, arg, type);
        }

        return TypeWrapper;
    }

    function formatDate(date) {
        var type = arguments[1];
        if(type == "Date") {
            return ('0'+ date.getDate()).slice(-2) + '.' + ('0'+ (date.getMonth() + 1)).slice(-2) + '.' +
                ('' + date.getFullYear()).slice(-2);
        }
        if(type == "Number") {
            date = new Date(date);
            return ('0'+ date.getDate()).slice(-2) + '.' + ('0'+ (date.getMonth() + 1)).slice(-2) + '.' +
                ('' + date.getFullYear()).slice(-2);
        }
        if(type == "String") {
            date = date.split('-');
            return ('0'+ date[2]).slice(-2) + '.' + ('0'+ (date[1] + 1)).slice(-2) + '.' + ('' + date[0]).slice(-2);
        }
        if(type == "Array") {
            return ('0'+ date[2]).slice(-2) + '.' + ('0'+ (date[1] + 1)).slice(-2) + '.' + ('' + date[0]).slice(-2);
        }
    }

    formatDate = getType(formatDate);

    alert (formatDate('2011-10-02')); // 02.10.11
    alert (formatDate(1234561488)); // 14.02.09
    alert (formatDate([2014, 0, 2])); // 02.01.14
    alert (formatDate(new Date(2014, 0, 1))); // 01.01.14

//ХОЧУ ВОТ ТАК:
function getType(f) {
        var type;
        function TypeWrapper(arg) {
            type = {}.toString.call(arg).slice(8, -1);
            return f.call(this, arg, type);
        }

        return TypeWrapper;
    }

    function formatDate(date) {
        var type = getType.type;
        if(type == "Date") {
            return ('0'+ date.getDate()).slice(-2) + '.' + ('0'+ (date.getMonth() + 1)).slice(-2) + '.' +
                ('' + date.getFullYear()).slice(-2);
        }
        if(type == "Number") {
            date = new Date(date);
            return ('0'+ date.getDate()).slice(-2) + '.' + ('0'+ (date.getMonth() + 1)).slice(-2) + '.' +
                ('' + date.getFullYear()).slice(-2);
        }
        if(type == "String") {
            date = date.split('-');
            return ('0'+ date[2]).slice(-2) + '.' + ('0'+ (date[1] + 1)).slice(-2) + '.' + ('' + date[0]).slice(-2);
        }
        if(type == "Array") {
            return ('0'+ date[2]).slice(-2) + '.' + ('0'+ (date[1] + 1)).slice(-2) + '.' + ('' + date[0]).slice(-2);
        }
    }

    formatDate = getType(formatDate);

    alert (formatDate('2011-10-02')); // 02.10.11
    alert (formatDate(1234561488)); // 14.02.09
    alert (formatDate([2014, 0, 2])); // 02.01.14
    alert (formatDate(new Date(2014, 0, 1))); // 01.01.14