Sep 15: Defining Functions, return

Learning Objectives

After today's class, you should be able to:

• Explain the flow of execution from one function to another.
• Describe the syntax of function definitions and function calls.
• Write short functions that have parameters and return values.

Announcements

• First Year Kick-off
  • Mon 9/18 at 5:00–6:00pm in King 159
  • Everyone in CS 149 or CS 159 is invited
  • Pizza and drinks will be provided!
  • RSVP now: https://jmu-cs.as.me/kick-off
  • Have you joined CS Advising on Canvas?
• Read Ch 4 – ideally:
  • 1st half before Friday
  • 2nd half before Monday
• Submit HW 4 – ideally:
  • 1 and 2 before Friday
  • 3 and 4 before Monday

POGIL Activity

• Defining Functions
  • If you are absent today, complete this activity at home
  • Bring your completed activity to class or office hours
• First use of Python Tutor

Example Code

Model 1

def model_one():
    word = input("Enter a word: ")
    L = len(word)
    ans = word * L
    print(ans)

def main():
    print("Starting main...")
    model_one()
    print("All done!")

main()

Model 2

def model_two(word):
    ans = word * len(word)
    print(ans)

def main():
    print("Starting main...")
    w = input("Enter a word: ")
    model_two(w)
    print("All done!")

main()

Model 3

def model_three(word):
    ans = word * len(word)
    return ans

def main():
    print("Starting main...")
    w = input("Enter a word: ")
    result = model_three(w)
    print(result)
    print("All done!")

main()