3 Functions

Question 1

What are parameters? Where can you see parameters and arguments in a function?

Answer 1

argument = value passed to a function (e.g. ‘Al’)
parameter = variable that contains an argument (e.g. ‘name’)
➊ def sayHello(name):
print(‘Hello, ‘ + name)
➋ sayHello(‘Al’)

Question 2

Functions are…

Answer 2

…the primary way to compartmentalize code into logical groups.

They are like black boxes: they have inputs in the form of parameters and outputs in the form of return values, and the code in them doesn’t affect variables in other functions.

Question 3

Why are functions advantageous to have in your programs?

Answer 3

Variables in a function exist in their own local scope and do not affect other functions local scopes. This limits potential error sources and helps debugging.

Question 4

When is a local scope created and when is it destroyed?

Answer 4

Function call: Local scope is created

Function return: Local scope is destroyed

Question 5

If a function does not have a return statement, what is the return value of a call to that function?

Answer 5

The Default Value is None

Question 6

How can you force a variable in a function to refer to the global variable?

Answer 6

def spam():
       global eggs
       eggs = 'hello'
-> Now eggs can be called outside the function

Question 7

What is the data type of None?

Answer 7

NoneType value - it represents the absence of a vallue

Question 8

How can you prevent a program from crashing when it gets an error?

Answer 8

With a Try and an Except clause

Question 9

What goes in the try clause? What goes in the except clause?

Answer 9

Try: Code that could potentially have an error
Except: Code that defines what should happen if an error occurs

def spam(divideBy):
    try:
        return 42 / divideBy
    except ZeroDivisionError:
        print('Error: Invalid argument.')

print(spam(2))

Question 10

How do you delay the output by 0.5 seconds?

Answer 10

import time

time.sleep(0.5)