The document provides a review for the upcoming CS151 midterm exam. It outlines the exam format which will be closed book, 50 minutes, with 11 questions and 1 extra credit question. Students must have an empty seat next to them during the exam. Topics that will be covered on the exam include booleans, strings, loops, scope of variables, dictionaries, and tracing programs. Students are advised to get sleep, eat before the exam, and have a positive attitude to manage stress for the midterm.

1. Computer Science 151
An introduction to the art of computing
Midterm Review
Rudy Martinez

2. CS151 Spring 2019
Midterm
When: 3/6 This Wednesday
Exam is 50 minutes.
Closed book, closed computer, no phones, no notes.
Exam is 11 questions 1 extra credit question
During the Exam everyone will need at least one seat empty next to them on
either side.

3. CS151 Spring 2019
Topics - Booleans:
● Know how the logic conditions work in Conditional statements:
If a > b then:
print(‘Hello’)
● Know And, Or statements
a = 5 b = 7 c = -1
If a > b AND a > c:
print(‘False’)
If a < b OR a > c:
print(‘True’)

4. CS151 Spring 2019
Topics - Strings
● Know what a string is
● Know how to get the individual characters:
myString = ‘Hello’
myString[4] → ‘o’
● Know how to get the length of a string.
● Know how to use a for loop to iterate over a string.
● Know how to concatenate two strings
● Know how strings are printed with print()

5. CS151 Spring 2019
Topics - Trace a Program
Know how a program flows:
myString = ‘Hello’
for i in range(0, len(myString), 1):
print(myString[i])
● Know what I is as the loop runs.
● Know how many times the loop will run
● Know what is being printed.

6. CS151 Spring 2019
Topics - Loops
● For loops
○ Know how to trace them
○ Know how to write them
● While loops
○ Know how to trace them
○ Know how to write them
for i in range(start, stop, increment)
# Do Stuff
while(boolean condition is true)
# Do Stuff
Increment variable that will lead to boolean
eventually being false.

7. CS151 Spring 2019
Topics - Scope of Variables
● Go back over lecture on Function it has everything you need to know about
scope of variables.
● Know what a global variable is and when it changes.
● Know variables in functions and when they can change.

8. CS151 Spring 2019
Global Scope vs Local Scope
a = 1
# Uses global because there is no local 'a'
def f():
print('Inside f() : ', str(a))
# Variable 'a' is redefined as a local
def g():
a = 2
print('Inside g() : ',str(a))
# Uses global keyword to modify global 'a'
def h():
global a
a = 3
print('Inside h() : ', str(a))
# Global scope
print('global : ',str(a))
f()
print('global : ',str(a))
g()
print('global : ',str(a))
h()
print('global : ',str(a))
global : 1
Inside f() : 1
global : 1
Inside g() : 2
global : 1
Inside h() : 3
global : 3

9. CS151 Spring 2019
Topics - Dictionaries
● Know how to create a dictionary
○ Mydictionary = {} # remember curly braces
● Know how to access a value using a key
○ Remember key:value pairs, every key has a value
○ Mydictionary{key} returns value
● Know how to iterate over them in a for loop
○ For loops!
○ For loops!
○ For loops!

10. CS151 Spring 2019
Stress Management
● Taking exams can be stressful to minimize this:
○ Get plenty of sleep, this help more than cramming for the test.
○ Eat a breakfast/lunch at least an hour before you take the test.
● Cramming doesn’t work, it really doesn’t.
● Positive attitude helps you with the right state of mind for the test.
● Show up to the test early and get ready.