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16 - Functions and Procedures

 1. Sub programs can be used to save time and simplify code. The two main types of sub programs are ________________________________

  parts and classes

  modules and definitions

  procedures and functions

  defs and parts

 2. The main difference between a procedure and a function (and this is for computing theory, so ignore any python syntax and specificity) is that....

  a function always returns at least two different values

  a function can perform many different functions and output the results

  a function always returns a single value to the main program.

  a function never returns a value to the main program

 3. What is an argument?

  An argument is a fight that occurs between two functions over a value

  An argument has nothing to do with computer science whatsoever

  An argument is a value that is passed into a function or procedure

  An argument is a type of procedure

 4. The following pseudo code converts an exam result to a grade using the given boundaries. Is the example shown below a procedure or function? 
Function GradeCalculator(score As Integer) 
STRING Grade
If Score>=90 THEN
	Grade = A*
If Score>=80 THEN
	Grade = A
If Score>=70 THEN
	Grade = B
If Score>=60 THEN
	Grade = C
Else
	Grade = Fail
Return (Grade)
End Function

  Neither

  Procedure because it has several functions inside of it

  Function because it returns, in the end, a single value 'Grade'

  Actually, the whole thing is called an 'argument' because it has many functions

 5. What will the output be if the input is '10'? #Extension: Try and code another function called 'multiply' which takes the input given by the user and multiplies it by itself.

  4

  10

  12

  2

 6. Consider the input and output for the following function print(fact(2))>> 2 print(fact(3))>> 6 What would the output be if called with '4' as shown below. 
def fact(x):
    if x < 2:
        return 1
    return x * fact(x - 1)

print(fact(4))

  12

  24

  10

  8

 7. In many languages, a function that does not return a value is called a ________________ (but do see the note below) 
>>It is worth noting in python that everything defined with a 'def' is 
called a function, and sometimes functions which don't return a value are
referred to as non-fruitful functions.
Source: http://interactivepython.org

  parameter

  procedure

  boolean

  argument

 8. Which of the examples below is a procedure? 
#Example 1

def square(x):
    y = x * x
    return y

toSquare = 10
result = square(toSquare)
print "The result of " + str(toSquare) + " squared is " + str(result)


#Example 2
def update_display():
    print("Your score: " + str(score))
	time.sleep(1)
	print("High score: " + str(high_score))
	time.sleep(1)
	print("Lives remaining: " + str(lives))
	time.sleep(1)

  Both examples are functions (they return a single value)

  Example 1

  Both examples are procedures (they perform multiple actions with multiple outputs)

  Example 2

 9. What is wrong with the following function definition? 
def addEm(x, y, z):
    return x+y+z
    print 'the answer is', x+y+z

  Both B and C are correct in this instance

  C - When the function gets to "return", it will immediately stop executing the function

  B - You should not have any statements in a function after the return statement.

  A - You should never use a print statement in a function definition

 10. What will the following code output? 
def square(x):
    y = x * x
    return y

print square(5) + square(5)

  50

  25+25

  Error

  25


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