on 17-Jul-2014 (Thu)

1. shorter can choose which bond to deliver and often when
2. futures are cheaper

Suppose we have a class that tries to cooperate with String. What is wrong with it?

public final class CaseInsensitiveString {

    private final String s;

    @Override public boolean equals(Object o) {
        if (o instanceof CaseInsensitiveString)
            return s.equalsIgnoreCase(((CaseInsensitiveString) o).s);
        if (o instanceof String)
            return s.equalsIgnoreCase((String) o);
       return false;
    }

    // rest of the code
}

Suppose we have a class

public class Point {
    private final int x;
    private final int y;

    @Override public boolean equals(Object o) {
	if (!(o instanceof Point))
	    return false;
	Point p = (Point)o;
	return p.x == x && p.y == y;
    }
    // Remainder omitted
}

and a subclass

public class ColorPoint extends Point {
    private final Color color;
    // Remainder omitted
}

what are the consequences of NOT implementing equals() method on ColorPoint?

Suppose we have a class

public class Point {
    private final int x;
    private final int y;

    @Override public boolean equals(Object o) {
	if (!(o instanceof Point))
	    return false;
	Point p = (Point)o;
	return p.x == x && p.y == y;
    }
    // Remainder omitted
}

and a subclass

public class ColorPoint extends Point {
    private final Color color;

    @Override public boolean equals(Object o) {
      if (!(o instanceof ColorPoint))
         return false;
      return super.equals(o) && ((ColorPoint) o).color == color;
     }

    // Remainder omitted
}

what are the consequences of implementing equals() method on ColorPoint like above?