// This is designed to illustrate several important concepts, including the use
// of static vs. non-static variables and methods, the use of multiple constructors,
// and the use of accessors (setters and getters) with private data.
public class Thing {
    // Static data
    private static int objectCount = 0;
    
    // Getter for the private objectCount variable.
    // Note that it has no setter.  We don't want it changed
    // anywhere but from within this class.
    public static int getObjectCount() { return objectCount; }
    
    // Instance variables
    private int a = 5;
    private int b = 7;
    
    // Constructors
    public Thing() { objectCount++; };
    
    public Thing(int alpha) {
        a = alpha;
        objectCount++;
    }
    
    public Thing(int alpha, int beta) {
        a = alpha;
        b = beta;
        objectCount++;
    }
    
    // Instance methods
    // The first 2 are setters and the next 2 are getters.
    public void setA(int alpha) { a = alpha; }
    public void setB(int beta) { b = beta; }
    public int getA() { return a; }
    public int getB() { return b; }
    
    public void print(String s) {
        System.out.println(s + ": " + a + " " + b);
    }
}