Chapter 5 Exercise Set 5: PCEP Practice

Invocation

The PCEP uses the term invocation where this text used a different term. Your task is to figure out which term that is, and then use that understanding to fill in the blanks in the following sentences.

1. By invoking a ________________, you cause it to execute.

2. Defining a ______________ does not make it run. It runs when it is invoked.

3. If you want your ___________ to return a value, you have to invoke it.

4. What is the output of the following program?

   expression = -1 ** 4 + 2 * 4 // 5
   
   if expression < 0:
       print('@')
   elif expression > 2:
       print('@@')
   else:
       print('@@@')
   

5. What is the output of the following program?

   def doit(val):
       for x in range(-1, 2):
           if 2 * x < 4:
               val += 1
       else:
           val += 2
       return val
   
   print(doit(-2))
   

6. What is the output of the following program?

   def do_something(thing):
       for r in range(1, 6):
           for c in range(-1, 3):
               if r == c:
                   thing += 2
               else:
                   continue
       else:
           thing -= 1
       return thing
   
   print(do_something(5))
   

7. What is the output of the following program?

   def make_it_happen(thing1, thing2):
       s = '*'
       while thing1 != thing2 and thing1:
           thing1 //= 2
           s += '*' 
       else:
           s += '!' 
       return s
   
   print(make_it_happen(16, 2))
   

8. What is the output of the following program?

   def f(x, y, z):
       return x + 2 * y + 3 * z
   
   print(f(0, z=1, y=3))
   

9. What is the output of the following program?

   def funky():
       n = 4
       while (n < 64):
           n *= 2
   
   obj = funky()
   print(obj)
   

10. What is the output of the following program?

    """
    Nothing here yet!
    """