# File: args.py
# Program to demonstrate how functions handle variables
#
# Matt Bishop, MHI 289I, Winter 2018
#

#
# this one shows passing parameters
# it just prints the 3 arguments
def func1(a, b, c):
    print "Argument #1:", a
    print "Argument #2:", b
    print "Argument #3:", c

#
# this one defines a local variable, x
# and assigns a value to it
def func2():
    x = 9
    print "func2: x =", x
    
#
# this one changes the value of a parameter
def func3(y):
    print "func3: y =", y
    y = 3456
    print "func3: y =", y
    
#
# the main program
#
def main():
    # first, show how arguments are passed
    func1(7, "hello", -3.14159)
    # now, show how local variables doesn't
    # affect variables in the caller
    x = 6
    print "main: x =", x
    func2()
    print "main: x =", x
    # finally, show how changing parameters
    # doesn't affect variables in the caller
    y = 21
    print "main: y =", y
    func3(y)
    print "main: y =", y
    
main()