function Worker (name, office, salary, city) {
   this.name = name;
   this.office = office;
   this.salary = salary;
   this.city;
}

// builder pattern

function WorkerBuilder() {
   var name = 'default name';
   var office = 'Goyello';
   var salary = 300;
   var city = 'Sosnowiec';

   return {
      name: function(name) {
        name = name;
        return this;
      },
      age: function(age) {
        age = age;
        return this;
      },
      office: function(office) {
        office = office;
        return this;
      },
      city: function(city) {
        city = city;
        return this;
      },
      build: function() {
        var worker = new WorkerBuilder(this);
        return worker;
      }
   }
}

var tomasz = new WorkerBuilder()
              .name('Tomasz')
              .age(29)
              .office('Facebook')
              .city('Sopot')
              .build();