comp sci loops
Which of the following for loops would print the following numbers? 3 5 7 9 for i in range(3, 10, 2): print i for i in range(3, 9, 2): print i for i in range(9): print i for i in range(3,9): print i
for i in range(3, 10, 2): print i
What will be printed to the screen when this program is run? for j in range(2): for i in range(0, 2, 1): print i 0 1 0 1 0 2 0 1 0 1 0 1 1 2 1 2 1 2
0 1 0 1
What does the following program print? for i in range(2): for j in range(2): print i + j 0 1 1 2 0112 0 1 0 1 0101
0 1 1 2
How many lines will this program print? x = 10 while x > 0: print x x = x - 3 3 4 5 6
4
What is the value of num when this loop completes? num = 0 for i in range(2, 8, 2): num = num + i 2 8 12 20
12
What is the value of sum when this loop completes? sum = 0 for i in range(3): sum = sum + 5 for j in range(2): sum = sum - 1 8 9 20 0
9
Which of the following best describes the purpose of a for loop? A for loop is for doing something an indeterminate number of times. A for loop is doing something an infinite number of times. A for loop is for doing something a fixed number of times. A for loop is for doing something three times.
A for loop is for doing something a fixed number of times.
Three of the for loops below will provide identical values for i. Which for loop will provide values that do not match the others? for i in range(0, 5): for i in range(5): for i in range(0, 5, 1): for i in range(5, 0, 1):
for i in range(5, 0, 1):
Which of the following while loops will cause an infinite loop? secret_num = 10 while secret_num == 10: secret_num = secret_num - 1 secret_num = 10 while secret_num == 10: print secret_num secret_num = 10 while secret_num > 0: secret_num = secret_num - 1 secret_num = 10 while secret_num != 10: print secret_num
secret_num = 10 while secret_num == 10: print secret_num
What will be printed to the screen when this program is run? num = 100 while num > 0: for i in range(100, 0, -25): num = num - i print num 100 0 -75 -125 -150 -150 -175 175
-150
Which of the following programs prints ten lines? for i in range(10): print "hi" for i = 1 to 10: print "hi" for i in 1 - 10: print "hi" for i from 0 to 9: print "hi"
for i in range(10): print "hi"
Which of the following for loops would print the following numbers? 0 1 2 3 4 5 for i in range(5): print i for i in range(1, 5, 1): print i for i in range(6): print i for i in range(0, 5, 1): print i
for i in range(6): print i
What does this program print? temperature = 65 while temperature < 80: print "It's still a nice day" if temperature < 70: temperature = temperature + 5 elif temperature > 75: break else: temperature = temperature + 3 It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day It's still a nice day
It's still a nice day It's still a nice day It's still a nice day It's still a nice day
When would a while loop be a better control structure to use than a for loop? When you need to repeat multiple commands When you need to repeat something 5 times When you don't know how many times something will need to repeat When the user is inputting how many times to repeat something
When you don't know how many times something will need to repeat
How many lines will this program print? while True: print "hi" 0 1 an infinite number of lines
an infinite number of lines
If I am using the following condition in my program: while True: which keyword should I use to make sure I don't create an infinite loop? break continue
break
Which of the following for loops will give the same values for i as the loop below? for i in range(10): for i in range(11, 0): for i in range(10, 0, -1): for i in range(0, 10): for i in range(0, 11, 1):
for i in range(0, 10):
Which of the following while loops would continue to loop as long as num has values in the range 3 to 12, exclusive? while num > 12 and num < 3: # do something with num while num < 12 or num < 3: # do something with num while num <= 12 and num >= 3: # do something with num while num < 12 and num > 3: # do something with num
while num < 12 and num > 3: # do something with num
What does this program print? for i in range(10): if i == 3: continue print i 0 1 2 0 1 2 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
0 1 2 4 5 6 7 8 9
Which Python keyword skips back to the beginning of a loop? break continue
continue
If the user enters '4', I want the loop to exit. Where should the break command be placed in order to end the loop when the user enters this value? Break and Continue On line 3 On line 5 On line 7 On line 9
On line 9
What is the benefit of using the break command as in the program below? magic_number = 10 while True: guess = int(input("Guess my number: ")) if guess == magic_number: print "You got it!" break print "Try again!" The user can enter as many answers as they want The program will break out of the loop as soon as the user enters the magic_number The loop will prompt the user to enter a number no matter what input they give The loop will give the magic_number after a certain number of tries
The program will break out of the loop as soon as the user enters the magic_number