Lecture 2 - Exercises

2A - Data Types

1. What is the result of each of the following function calls?
   1. type(7.0)
   2. type("7.0")
   3. type(7)
   4. float(7)
   5. str(7.0)
   6. type(3+4)
2. If you pass a positive float argument to the int function, which of the following does it do?
   • Throw an error
   • Round to the nearest integer
   • Always round down
   • Always round up

2B - Variables and Assignment

3. Which of the following does not print the same thing as the others?

   Program A:

   a = 14
   b = 3
   print(a, b)

   Program B:

   a = 3
   b = 14
   print(14, 3)

   Program C:

   a = 14
   b = a
   print(a, b)

   Program D:

   a = 3
   b = 14
   print(14, a)

4. Consider the following program:

   a = 5
   b = 5
   a = 6
   b = 7

   After this program executes, what values do a and b hold?

5. What does the following program print?

   x = 3.0
   m = 2.0
   b = -4.0
   y = m * x + b
   print(y)

Problem

Suppose that you are writing a program and you have two variables x and y that contain values. You’d like to swap the values stored in those variables, so what was previously stored in x is now stored in y and what was stored in y is now in x. For example if the following program is completed with your code, it should output 4 10. Note: your solution should not depend on the specific values (e.g., 4 and 10) - it should work regardless of what x and y are set to.

x = 10
y = 4
# your code here
print(x, y)