AP Computer Science

variable

a box that can hold one value at a time, such as one word, one costume, or one list (which can contain many things); you can look at what's inside as many times as you want

data abstraction

giving names to numbers, text, lists, etc; when you give something a name, you can refer to it without knowing exactly what the value is; the creation and use of abstract data types in a program

local variable

can be set or used only in the environment in which it is defined; this term includes inputs to procedures and variables created by the for or script variables block

Repeat until

a loop (just like repeat, forever, and for) but also a conditional (like if and if else); it repeats until a certain condition is met

predicate

a hexagon-shaped reporter that asks a true/false question; report a boolean value

Boolean value

either true or false

conditionals

control the code based on a true-or-false condition; i.e. if and if-else blocks

bug

an error in the code that makes the program behave differently than expected

global variable

a variable that is usable by all scripts in the program

Initialization

setting the starting value of a variable

index

the position number of an item in a list; the position of a character in a string (for example, a letter in a word)

element

another name for an item in a list (if the same value is in the list twice, that counts as two different elements); each element has a unique index (position) in the list

sublist

a list as an item of another list

data type

is what kind of data something is (number, text string, list, etc.)

primitive data types

data types that are built-in to each programming language

abstract data type (ADT)

a custom data type that's meaningful to your program; it's not built into the language - you develop it as you code; this is an abstraction because it hides the details inside the constructor and selectors

constructor

constructs one example of the data structure; by naming the pieces of the structure, the constructor makes it certain that every time you use it, you build the structure in the right order

selectors

they each select one piece of the data structure

composition of functions

using the result from an item as the input to address from contact

traversing a list

looking at each item of the list

input type (or domain)

the type of data that it accepts as input

output type (or range)

the type of data that it reports as output

selection

deciding (selecting) which part of an algorithm to run based on whether a condition is true or false; every algorithm can be constructed using sequencing (following steps in order), selection (deciding), and iteration (repeating)

nested conditional statement

an if or if else statement inside the else part of another if else statement; if the predicate of the outer if else statement is false, then inner (nested) conditional statement will test its predicate and decide what to do

string

an ordered sequence of characters

mod block

reports the remainder when the first input is divided by the second

software library

a collection of procedures that can be used in programs

application program interface (API)

documents what a programmer needs to know about using a library: it's a description of each procedure's purpose, inputs, and outputs (but not its algorithms)

web API

a call to a procedure on another machine

plagiarism

pretending that you wrote someone else's work

Creative Commons

a specific copyright license that allows others to use, share, and revise your work

Free software

software that anyone can copy, use, modify, and redistribute

Open source software

a more general term that means that a software's owner put the program's code online, but they may still restrict how people can use the program

Open access scholarly research reports

available for free download, rather than requiring the permission of a journal publisher

Digital Rights Management (DRM) software

publishers get copyright protection during the time when a work is most popular and control over the content forever

Digital Millennium Copyright Act (DMCA)

a US law that went into effect in 1998; it makes it a crime to figure out how to defeat DRM systems, whether or not a copyright is actually violated