CPSC 120 -- Final Exam Review Topics

• Operating Systems (Linux overview and lab 0)
  • Know what an operating system is
  • Know the two main tasks of an operating system. Know what some of the particular tasks are in the "managing the hardware resources of the computer" category - what specifically is the operating system in charge of? (See the Linux/Unix Overview).
  • Understand the file structure of the Unix (Linux) operating system --- the tree-like organization, the absolute (full) and relative pathnames for files, shorthand notation for certain files (the dot, tilde, etc.)
  • Understand the idea of file permissions -- what they are, what they mean, how you can find out the permissions in Linux
  • Know what a shell is and know the basic Linux shell commands we have used

• Compilers, Interpreters and Languages (Linux overview and lab 0)
  • Know the programming language hierarchy
  • Know what compilers and interpreters are and what each does (and how they differ) - know the role of these in our use of Java (when are we using a compiler and what does it do and when are we using an interpreter and what does it do)
  • Know the difference between the source file and the file containing bytecode - know the role of each in the compilation process and know the rules for the names of each type of file (i.e., what must the source file be named, what is the name of the file created by the compiler?)
  • Know the difference between bytecode and machine code

• General Programming Concepts (Chapter 1 and lab 1)
  • Problem solving steps
  • General idea of object oriented programming - what is an object, what is meant by the state of an object, what is meant by the attributes and behaviors of an object, what is a class, what are methods?
  • Syntax versus semantics
  • Comments/Documentation
  • Use of White Space
  • Levels of programming languages (hierarchy)
  • Types of errors in programming (syntax or compile-time, run time, logic)
  • Understand the coordinate system for Java graphics

• Basic Programming Constructs (Chapter 2, labs 1 and 2)
  • Identifiers -- what one is, syntax rules for identifiers in Java
  • Variables - what they are, the difference between what is stored in a variable of primitive type and one for an object
  • Declaration of named constants (final) & the reason for using these
  • Primitive Data types in Java
  • String and numeric (int, double, char) literals -- syntax
  • Data conversion - automatic widening conversions, explicit narrowing conversions through type casting
  • Output - printing using print and println (including + and escape sequences)
  • Input - setting up a Scanner object, prompting the user, reading input using the appropriate method (nextInt, nextDouble, nextLine)
  • Escape sequences - what they are, how to use, why they are needed
  • Assignment Statements - syntax and how one is executed
  • Expressions (including the arithmetic operators and the precedence and associativity rules) - be able to write expressions for computations; be able to evaluate expressions exactly as the computer would (including those that contain strings and + as concatentation) and show the results.
  • Print and println statements - be able to determine exactly what will be printed by a given statement; be able to write statements to print in the exact format given.

• Objects, Classes, and Methods (Chapter 3 and labs 3 and 4)
  • Be able to distinguish between an object and a class
  • Be able to declare a variable to be a reference to an object
  • Be able to instantiate an object with the new operator; understand that this invokes a constructor method for the class to initialize the object.
  • Understand the use of the dot operator to invoke (call) a method
  • Be able to look at the signature of a method and from that determine how to invoke the method
  • Know how one invokes a static (class) method
  • Know the basics of using the String class, the Math class, the Scanner class, and the Random class (be able to write an expression to generate a random number in a given range).
    • In the String class know how to use the following methods: charAt, length, replace, substring, toLowerCase, toUpperCase
    • In the Random class know how to use the following methods: nextInt, nextDouble
    • In the Math class know how to use the following methods: sqrt, pow.

• Syntax and Semantics
  • Be able to find syntax errors in a Java program
  • Be able to describe the semantics of statements we have studied (for example, what does the computer do with a variable declaration, what is the relationship between memory and a variable declaration, how is an assignment statement executed, how are expressions evaluated?)
  • Be able to trace the execution of a program (show what it would do in a step by step manner)

• 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 representation.
  • 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 complement.
  • 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 use braces!!!
  • 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 or compareTo).
  • Know about the boolean data type -- how to declare a boolean variable and assign the result of a boolean expression to the variable.
  • 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 it.
  • Be able to trace code with if statements, switch statements, and boolean expressions to show what it would do (or to determine if it is correct).

• Logic (Handouts on logic and circuits)
  • 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/ logic statements).
  • 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 truth tables. to find equivalent but simpler 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 control condition
    • 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, find products.
  • 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).

• Loops (Sections 4.5 (while - this was on the last test but you still need to know how to do them!), 4.7 (do...while), 4.8 (for loops), Labs 7 - 10, class notes, quizzes)
  • Know the three basic loop structures and the differences among them; given a loop of one type (for example, while) be able to write an equivalent loop of another type.
  • Be able to trace a loop to determine what it does - this includes showing values of variables as it executes, showing what it prints, or giving a verbal high-level description (such as finds the product of the multiples of 3 from 1 to n).
  • Be able to write loops -- be able to correctly control the loop (write the appropriate boolean expression for the loop control condition, initialize any variables in that expression (loop control variables) before the loop, update those variables correctly inside the loop).
  • Know what is meant by a count-controlled loop (and how to write one especially using a for statement) and a sentinel controlled loop (and how to write one).
  • Be able to perform common looping subtasks -- summing, counting, finding averages, finding products, finding max and min values. Be able to use a loop to go through a string character by character and do something such as count a particular type of character or find the first character after a blank. Be able to use a loop to ensure valid input (keep making the user enter values until the value is in the correct range).
  • Be able to write and understand complex loops containing method calls, conditions, and other loops (nested loops).

• Objects and Classes (Sections 3.1, 5.1 - 5.8, Labs 3 and 8 - 10, class notes and handouts - All Self-Review Questions in Chapter 5, except 5.5 on page 224 are good review.)
  • Understand the difference between objects and primitive values, including the difference in how they are stored (directly vs. references).
  • Be able to create (instantiate) an object given the type signature of one or more constructors of the appropriate class.
  • Be able to use an object appropriately given the type signatures and reasonable documentation for its methods.
  • Understand the meaning of the public and private modifiers and when each is appropriate.
  • Understand the meaning of encapsulation (related to the idea that an object should be self-governing) and how visibility modifiers are used to enforce it (specifically understand what parts of the class should be private and what should be public and how doing that enforces encapsulation).
  • Understand the concepts of attributes and behaviors (or operations) of objects and how these relate to instance variables and methods in the classes we write.
  • Understand the difference between instance data (variables) and local data (variables).
  • Be able to write a class given a description of the capabilities required of it.
  • Know what an alias is and what garbage is! (Section 3.1)
  • Understand the difference between static and instance variables, and when each should be used. Understand why we often make constants in a class public and static and how a client program can access them.
  • Know what the reserved word this is.

• Methods (Chapter 5 but especially sections 5.4, Labs 3, and 8 - 10, class notes and handouts)
  • Be able to write a method to perform a given task.
  • Know what a constructor is and how a constructor differs from other methods (when a constructor is executed and other differences). Be able to write constructors.
  • Understand the role of the toString method - what it does and how it is used implicitly when an object is included in a print statement. Understand what happens if you try to print an object for a class that does not have a toString method.
  • Understand all components of a method's signature -- public/private, static/instance, return type, method name, formal parameters.
  • Understand what it means for a method to return a value, and be able to both write and use such methods. In particular, understand the difference between a method that has void return type and one that returns a value.
  • Understand the difference between formal and actual parameters.
  • Understand the scope of identifiers - where formal parameters can be referenced, where local variables can be referenced, where instance variables can be referenced. (pp. 170-1, 188-190)
  • Understand the difference between static and instance methods, how each is accessed, and when each should be used. (Section 3.6, the Math class, Self Review Question SR 5.11 on page 224)
  • Understand what it means to say a method is overloaded. Be able to explain how overloaded methods can be distinguished from each other.

• Arrays (Chapter 7 (except Section 7.5), Labs 11 and 12, class notes, quizzes)
  • How to declare and initialize an array (both of primitives and objects), including the default values of various types, and array literals.
  • Be able to iterate over an array to perform actions such as, average, min, max, sum, printing, finding, and converting to a string.
  • Understand how arrays are stored in memory and how they are passed as parameters to methods.
  • Know how to store a variable number of objects in an array (i.e. use a counter to record how many elements are in the array, and expand or contract the array as needed.)
  • How to create and use multidimensional arrays including ragged arrays.