uml classdiagram constructor with parameters

Question

I am a complete ROOKIE at this so I need some help on it.

How would you create uml class diagram and constructors with parameters.

for default (no parameters) you do

policyholder() for diagram and pseudo-code

for parameters would you do the same thing

policyholder (policynumber, service class, and customer age) for class diagrams and pseudo-code.

It also asked to initialize each attribute to value where an object of this type can be instantiated, If a policy number is not between 1000 and 999 inclusive, then set the policy number to 0. (policy number is attribute)