Functions - one parameter

Parameter

A parameter is like a placeholder. When a function is called, you pass a value to the parameter.

1 def function_name(parameter):	The keyword def indicates a function is defined. function_name must follow variable naming rules. Parameter is passed in parenthesis.
2 <indented block>	Indented code to perform some action.

Example 1

Write a function that squares a number. In the menu option, ask the user for a number. Call the function square with the user’s number as the value. Create a function named square. Print the square of the number.

example1.py

def main():
  done = False
  while not done:
    print("Menu")
    print("E1 - Example 1")
    print("Q - Quit")
    choice = input("Choice: ")
    if choice == "E1":
        num = int(input("Give me a number: "))
        square(num)
    elif choice == "Q":
        print("Exiting Game!")
        done = True

def square(num):
  print(num, "squared is", num**2)

main()

Example 2

Write a function that determines if a number is even. In the menu option, ask the user for a number. Call the function even with the user’s number as the value. Create a function named even. If the number is even, print the number is even.

example2.py

def main():
  done = False
  while not done:
    print("Menu")
    print("E2 - Example 2")
    print("Q - Quit")
    choice = input("Choice: ")
    if choice == "E2":
        num = int(input("Give me a number: "))
        e1(num)
    elif choice == "Q":
        print("Exiting Game!")
        done = True

def even(num):
  if num % 2 == 0:
    print(num, "is even")

main()

Example 3

Write a function that calculates the summation of a number. In the menu option, ask the user for a number. Call the function summation with the user’s number as the value. Create a function named summation.

example3.py

def main():
  done = False
  while not done:
    print("Menu")
    print("E3 - Example 3")
    print("Q - Quit")
    choice = input("Choice: ")
    if choice == "E3":
        num = int(input("Give me a number: "))
        e1(num)
    elif choice == "Q":
        print("Exiting Game!")
        done = True

def summation(num):
  print(num*(num+1)/2))

main()