# Author:  James Tam
# Version: November 17 2010
# An example to illustrate error handling using exceptions vs. using
# a standard if construct. For simple examples like this you won't really
# find a major difference between the two approaches. (Fun2 shows a bit
# of information about the function calls if you enter a negative value).
# If you take CPSC 233 you will see cases where handling an error using an 
# exception is much better than using a series of if's.


# Error checks using a standard branching construct
def fun1 (age):
   if (age < 0):
      print "age can't be negative"

# Error checks by creating an exception
def fun2 (age):
   if (age < 0):
      raise ValueError, "age can't be negative"

def main ():
   age = input ("What's your age? ")
   fun1 (age)
   age = input ("What's your age? ")
   fun2 (age)

main ()