// demonstrates static/non-static fields and methods
// simulates a person (not in the Blade Runner sense)
public class Person {
 // instance variable: age of this person
 private int age; 

 // another instance variable: name of this person
 private String name; 

 // static variable (shared by all instances): global population
 private static int population = 0;
 
 // constructor
 public Person(int a, String n) {
 // copy arguments of constructor to instance variables
 age = a;
 name = n;

 // increase the static counter
 population++;
 }

 // static method (not per-instance)
 public static void printPop() {
 System.out.println(population);
 }

 // instance method
 public void printName() {
 System.out.println(name);
 }

 // another instance method
 public void printInfo() { 
 System.out.println(age);
 
 // calling an instance method without a period
 // (uses same instance as what printInfo was called on)
 printName();
 }

 public static void main(String[] args) {
 // calling a static method using class name and period
 // what is the output?
 Person.printPop(); 
 
 // how many instances does this construct?
 Person myDad = new Person(33, "Lucius");
 Person myMom = new Person(44, "Pandora");
 Person myDentist = myMom;

 // calling an instance method using instance name and period
 myDentist.printInfo(); 
 
 // calling a static method without a period
 // (uses Person, the containing class, by default)
 // what is the output?
 printPop();
 }
}