AP CS A Vocab Review

Modulus

%; allows for checking divisible compatibility or lowering number of digits in a number

element

A stored value in an array

Truth table

A table used as a convenient method for organizing the truth values of statements

GUI (Graphical User Interface)

A type of interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, as opposed to text-based interfaces, typed command labels or text navigation.

Constant

A value that does not change

Boolean Expression

In programming, an expression that evaluates to True or False.

Argument

Independent items, or variables, that contain data or codes. When an argument is used to customize a program for a user, it is typically called a "parameter."

println

Method that displays output to the screen and then moves the insertion point to the next line.

String literal

Text enclosed by double quotes

extends

The keyword _____ creates the inheritance relationship //example public class Manager ____ Employee { }

object class

The name of the Java class that is the "mother" of all objects. All other Java class automatically inherit the Object class as the top-level parent class in the hierarchy. This class provides basic methods such as the toString, hashCode, and equals methods.

Return type

The part of the method that specifies what a method call will return.

compareTo method

Uses a string, a dot, and the method name. When it returns 0, the two strings are equivalent; when it returns a positive number, the first string is greater than the second; and when it returns a negative value, the first string is less than the second.

Non-static

Without the static keyword, members of the class belong to instances or objects of the class.

if and if-else

conditional statements

overloading a method

giving two methods the same name but different method signatures

Constructor

A sequence of statements for initializing a newly instantiated object

Math class

A set of mathematical functions used to build complex expressions.

Memory address

A specific location in memory where instructions or data are stored

Dot operator

The dot operator (.) permits access to attributes and functions of a module (or attributes and methods of a class or instance - as we have seen elsewhere).

Condition

the way someone or something is

OOP (Object Oriented Programming)

"A method of programming which classifies real world objects into classes and encapsulates those objects attributes and behaviours."

Parameter

(n.) a determining or characteristic element; a factor that shapes the total outcome; a limit, boundary

Increment

(n.) an enlargement; the process of increasing (The workmen made the wall longer, increment by increment.)

Compiler

A computer program created to read an entire program and convert it into a lower-level language and ultimately to assembly language used by the processor.

N-arg constructor

A constructor used when an n number of parameters are used; overloads the default

Primitive variable

A label referring to a location in memory containing a value that can be accessed or changed by a program

DeMorgan's Law

A law of logic that is used to simplify conditions in which ! (not) operators are applied to && or || (and/or) expressions; && switches to || and || switches to && and reverse < > <= and >=

Nested loop

A loop inside the body of another loop.

Boolean Algebra

A mathematical notation for expressing two-valued logical functions

initializer list

A means of expressing a set of data that can be assigned to the cells of an array in one statement.

printf

A method of the System class that is capable of outputting formatted text.

Numeric literal

A number that is written into a program's code

Driver

A program that determines how a computer will communicate with a peripheral device

while loop

A programming construct used to repeat a set of commands (loop) as long as (while) a boolean condition is true

IDE (Integrated Development Environment)

A programming environment that includes an editor, compiler, and debugger

Terminal I/O user interface

A user interface that allows the user to enter input from a keyboard and view output as text in a window.

Object variable

A variable that holds the memory address of an object and allows you to work with the object

Reserved word

A word that has a special meaning in a programming language and therefore cannot be used as a name by the programmer.

Data type

All values in a programming language have a "type" - such as a Number, Boolean, or String - that dictates how the computer will interpret it. For example 7+5 is interpreted differently from "7"+"5"

Escape sequence key

An ___________________ character, \, followed by one or more printable characters used to designate a nonprintable character.

Object

An abstract data type created by a developer. It can include multiple properties and methods and may even contain other objects.

Array

An arrangement of objects in equal rows.

Initialization

An assignment that gives an initial value to a variable that will be updated.

Identifier

An attribute (or group of attributes) whose value is associated with one and only one entity instance

Logic Error

An error in a program that makes it do something other than what the programmer intended.

Run-Time Error

An error in a program that makes it impossible to run to completion. Also called an "exception".

ArithmeticException exception

An exception thrown when division by 0 occurs.

instance variable

An identifier whose scope is a whole object.; A variable defined in a class for which every object of the class has its own value

Mutator

An instance method that modifies the object's internal state. Also known as setter

Accessor

An instance method that provides information about the state of an object without modifying it. Also known as getter

Byte Code

An intermediate language between source code and object code. Many modern languages first compile source code into byte code and then interpret the byte code with a program called a virtual machine.

Scope

Area of the program where an item (be it variable, constant, function, etc.) that has an identifier name is recognized

And, or, not

Boolean operators

Parity

Can have more than one reference to the same object. (Usually done by accident)

Resource Class

Class which holds the methods needed to be implemented in another class (seen as blueprint)

Instantiate an object

ClassName objectName = new ClassName(); Create an object of a particular class. For example, my_triangle = Triangle(90, 30, 60)

Source code

Contains instructions written by a programmer specifying the actions to be performed by computer software

Behavior

Defined by its methods, which are the functions and subroutines defined within the object class.

Round-off Error

Error that results when the number of bits is not enough to represent the actual number, like 3 digits to represent π as 3.14

Assigning

Giving a variable a value

Null

If you declare an object and never call a constructor

Declaring

Indicating to the compiler what type of variable you want and its name or identifier

do-while loop

Iterate while the condition is true do { ... this thing } while(condition);

State

Its condition regarding stored inputs

"this" method

Keyword in Java which is used as a reference to the object of the current class, with in an instance method or a constructor. Using this you can refer the members of a class such as constructors, variables and methods.

User Input

Methods created/used to receive data from a user.

Logic operator

One of the operators that combines boolean expressions: ( not , and, or )

Reference

Provides a way of recording address information about objects which themselves are not directly bound to the naming/directory system

Pointer

References a location in memory, and obtaining the value stored at that location is known as dereferencing the __________.

operator shortcuts

Shortcuts that can be used to shorten the length of writing a statement; ex. num = num + 1 --> num++

Hasa

Simply means that an instance of one class has a reference to an instance of another class or an other instance of the same class

Isa

Simply means that an instance of one class is a reference to an instance of another class or an other instance of the same class

JVM (Java Virtual Machine)

Software inside various electronic platforms that reads and runs compiled bytecode.

reference variable

Stores (points to) the memory address of an object

Casting or Typecasting

Temporarily assigning a different data type for a variable

Assignment operator

The '=' character causes the compiler or interpreter to evaluate to the expression on its right and store the result in the variable(s) on its left.

default constructor

The constructor called from a class's superclass when no constructor is provided.

Input/Output (I/O)

The manner in which data is received into a computer system, and the manner in which information and the results of processing are provided to the user from a computer system

Initializing

The process of assigning a beginning value to a memory location, such as a counter or accumulator variable

equals method

This determines whether two different String objects contain the same string.

Decrement

To subtract a certain amount (1), once or many times

Relational Operators

Used to compare two values. Operators include =,<,>,<=,>=,<>

Data field

Usually includes field structure (size of each field and whether it is a date, an integer, or a text field) and field organization (names and locations of data fields within a document record)

Static

Utility methods that we want to expose to be used by other classes without the need of creating an instance.

Index

Variable used to indicate the order of data in an array starting from 0

short circuit evaluation

When a boolean expression is evaluated the evaluation starts at the left hand expression and proceeds to the right, stopping when it is no longer necessary to evaluate any further to determine the final outcome.

keyword

Words that have a specific function in Java language

API

a collection of commands made available to a programmer; Application Programming Interface

Distributive Property

a property indicating a special way in which multiplication is applied to addition of two or more numbers in which each term inside a set of parentheses can be multiplied by a factor outside the parentheses, such as a(b + c) = ab + ac

conditional statement

a statement that can be written in if-then form

Method

a way of doing something, especially a systematic way

print command

displays something on the screen; can also be used to create blank lines of space on the screen

toString method

formats a number stored in a numeric variable and then returns the result as a string

Concatenate

link together; usually in a print statement

overriding a method

redefining a method in a subclass

Compiler Error

syntax error

Truncate

to cut off; used when dividing by an integer

traverse

travel across or through an array

Scanner class

used to create objects that can read primitive type values from the keyboard.