AP Computer Science A Exam Review

AP Computer Science A Exam Review Flashcards

Identifier

Name for variable, parameter, constant, user-defined method/class, etc.

Built-in/Primitive Types

int, boolean, double

int

An integer, e.g. 5, -77, 9001

boolean

A boolean, true or false

double

A double precision floating-point number, 2.718, -3456.78, 1.4e5

Integer.MINVALUE and Integer.MAXVALUE

Represent the absolute lowest and highest values that can be stored in an integer

final variable

A quantity whose value will not change

+

Addition

-

Subtraction

*

Multiplication

/

Division

%

Mod (remainder)

Integer division note

Integer division truncates the answer (cuts off the decimal)

==

Equal to

!=

Not equal to

Greater than

<

Less than

=

Greater than or equal to

<=

Less than or equal to

!

NOT

&&

AND

||

OR

=

Simple assignment

+=

x = x + 4

-=

y = y - 6

*=

p = p * 5

/=

n = n / 10

%=

n = n % 10

++

k = k + 1

--

i = i - 1

Conditional Control Structures

if, if…else, if…else if

Looping Control Structures

while loop, for loop, for-each loop

Constructors

Create an object of the class

Accessor

Gets data but doesn’t change data

Mutator

Changes instance variable(s)

Static methods

Class methods, deals with class variables

Method Overloading

Two or more methods with the same name but different parameter lists

Inheritance

Where a subclass is created from an existing superclass

Class hierarchy

Superclass should contain the data and functionality that are common to all subclasses that inherit from the superclass

Implementing Subclasses

Subclasses copy everything except constructors

Inheriting Instance Methods/Variables

Subclasses cannot directly access private variables if they are inherited from a superclass

Method Overriding

If a method has the same name and parameter list in both the superclass and subclass, the subclass method overrides the superclass method

Super

Call up to the superclass

Polymorphism

Method overridden in at least one subclass is polymorphic

Abstract Class

Superclass that represents an abstract concept

Interface

Collection of related methods whose headers are provided without implementations

List

Basically the same as ArrayList

Lists and Arrays

Search, delete and insert an item.

1-D Arrays

First index starts at 0

Array Length

length is a public instance variable of arrays

Traversing an Array

Use for-each loop when you need to access (only access) every element in an array without replacing or removing elements

Selection Sort Algorithm

Search and swap

Insertion Sort Algorithm

Check element (store in temp variable). If larger than the previous element, leave it. If smaller than the previous element, shift previous larger elements down until you reach a smaller element (or beginning of array). Insert element.

Merge Sort Algorithm

Divide data into 2 equal parts, Recursively sort both halves, Merge the results

Binary Search

Check middle element. Is this what we’re looking for? If so, we’re done. Does what we’re looking for come before or after? Throw away half we don’t need. Repeat with half we do need

Binary search

Recursive

GridWorld Case Study

Bugs and Critters are 25% of the exam

Bug Methods

Bug moves if possible; otherwise turns.

BoxBug Variables

number of steps in a side of its square

Critter Class

Get a list of neighboring actors, Process actors, Get list of possible locations to move to, Select location from list, Move to location