Untitled

<html>
<script>
    function Worker (name, surname, rate, days) {
        var salary =0;
        this.getName = function () {
            return name;
        };
        this.getSurname = function () {
            return surname;
        };
        this.days = function (value) {
            if (!arguments.length) return days;
            if(value>=10&&value<=31)
                days=value;
            else
                throw "Чо то не так"
        };
        this.rate = function (value) {
            if (!arguments.length) return rate;
            else
                rate=value;
        };
        this.salary = function (value) {
                return  rate*days;
            };
    }
    var worker = new Worker("Работяга","Работягович",10,31);
   worker.rate(20);
   worker.days(10);
   console.log(worker.salary())
</script>
</html>