//
// Supporting material for lecture 11
// - helper methods
// - validating time, again :)
// read in two times and then do soemthing with them!!!
//
import FormatIO.*;

public class Demo11 {

    private static boolean validTime(int x){
	return x > 0 && x/100 < 24 && x%100 < 60;
    }

 public static void main(String[] args){
	Console con    = new Console();
	int firstTime  = -999,
	    secondTime = -999;
	while (!validTime(firstTime)){Discuss, how ca
	    con.print("Enter first time: ");
	    firstTime = con.readInt();
	}
	while (!validTime(secondTime)){
	    con.print("Enter second time: ");
	    secondTime = con.readInt();
	}
	con.println("Diff: " + (firstTime - secondTime)); // (9)
 }
}
//
// method tests if time is valid
// note parameter passing and what method returns
// why bother? 
// - neater?
// - easier to get right?
// - easy to reuse (as a tool)
// Can you make diff (9) more sensible?
//  - write a diff method?
//
// NOTE: variable names, initial values and why we choose these,
//