CPSC 120 -- Test #2 Review
- Machine Representation of Integers (Class notes, handout on
twos complement, Lab 5 Prelab and Lab, exercise handouts, Section 2.3
and Appendix B of the text)
- Be able to convert a number in any base to its equivalent base 10
- Be able to convert a base 10 number to any other base.
- Be able to convert among bases 2 (binary), 8 (octal), and 16
(hexadecimal) without using base 10.
- Be able to find the n-bit (where n is specified) twos complement
representation of a base 10 integer (positive or negative).
- Be able to find the base 10 value of a number represented in twos
- Be able to find the largest (and smallest) base 10
unsigned number that can be
stored in n-bits; be able to find the largest (and smallest)
base 10 signed twos complement
number that can be stored in n-bits.
- Be able to add base 2 and twos complement numbers; understand the
problem of overflow (what it means and how to recognize it)
and be able to demonstrate it.
- Selection Statements and Boolean Expressions
(Sections 4.1 - 4.4 of the text plus handouts, labs and prelabs)
- Know how to write if ... else ... statements in their various
forms (with no else clause, nested, cascading). Know when you need to
- Know how to write and evaluate boolean expressions using relational
operators (such as == and <=) and boolean operators (&&, ||, and !);
know that the relational operators such as == work only on primitive data
not on objects (to compare objects you must use methods - equals
- Know about the boolean data type -- how to declare a boolean
variable and assign the result of a boolean expression to the
- Know how to write a method with a boolean return type.
- Know that the switch statement is another selection
statement that can be used when your selection condition is to
test to see if a single variable is equal to one of several different
possible values (the cases in the switch). Understand the role
of the break statement in the switch -- without it once a
condition is true all remaining statements in the switch would be executed
rather than just the one where the condition is true. You will not
have to write a switch statement on the test but you may be asked
some general question or given a switch statement and asked something about
- Be able to trace code with if statements, switch statements, and
boolean expressions to show what it would do (or to determine if it
- Logic (Handouts - one labeled "Logic" and one labeled "Logic
and Programming Exercises")
- Know the logic operators AND, OR, and NOT and both the mathematical
and Java symbols for these.
- Be able to construct truth tables for boolean expressions (propositions/
- Know DeMorgan's law of logic - be able to use it both on mathematical
statements and in the context of programming.
- Be able to show two boolean expressions are equivalent using
- Be able to use the laws of logic (DeMorgan's, Distributive, Idempotent, etc.)
to simplify statements.
- Understand the connection between logic and computer circuits. In particular,
be able to write a logic statement equivalent to a given circuit, be able
to use the laws of logic to simplify the statement and construct a simpler
but equivalent circuit, be able to constuct a circuit given either a truth
table for its output or a verbal description of the behavior of the circuit.
- While Loops (Section 4.5 & Lab 7)
- Understand how loops work - be able to trace the execution of a loop
showing the value of each variable as the loop executes and/or showing
the output of the loop.
- Be able to write loops. In particular, be able to correctly
do each part that goes into writing a loop:
- write the correct boolean expression for the loop
- initialize variables before the loop
- update the loop control variable(s) inside the loop
- perform the processing inside the loop (do whatever the loop
is supposed to do!)
- Specifically be able to write loops that do the following
standard looping tasks: count, sum,
find averages, force the user to enter valid input,
- Know how to recognize and write count-controlled loops
and sentinel controlled loops.
- Testing (Lab 6)
- Be able to determine test cases to test a program (a) when there
are many different paths through a program (such as Rock, Paper, Scissors)
and (b) when a value should be in a specific range (such as the Date program).