enum doubt

[zartab ameen]

Hi this is one of the question i found in mock exam

class Stepper{
enum Roman {I,V,X,L,C,M}
public static void main(String... bang){
int x=7;
int z=2;

Roman r=Roman.X;
do{
switch(r){
case C:r=Roman.L;break;
case X:r=Roman.C;
case L:if(r.ordinal()>2)z+=5;
case M:x++;
}
z++;
}while(x<10);
System.out.println(z);
}
}
---------------------------
output:21
---------------------------
i have just one statement which i did not understand

case L:if(r.ordinal()>2)z+=5;
please can you explain me what does above statement mean,i really don't
understand what ordinal is.

THANK YOU

[Julio Eneriz]

From the Api (http://java.sun.com/j2se/1.5.0/docs/api/) Enum page


ordinal()
Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero).


So the behaviour depends on the ordinal I = 0, V = 1, X = 2 and so on, so L,C and M > 2.

What I'm not sure is the purpose of the code.