AP Computer Science Principles Vocabulary (from Code.org)

Algorithm

A precise sequence of instructions for processes that can be executed by a computer

High Level Programming Language

A programming language with many commands and features designed to make common tasks easier to program. Any high level functionality is encapsulated as combinations of low level commands.

Low Level Programming Language

A programming language that captures only the most primitive operations available to a machine. Anything that a computer can do can be represented with combinations of low level commands.

Iterate

To repeat in order to achieve, or get closer to, a desired goal.

Selection

A generic term for a type of programming statement (usually an if-statement) that uses a Boolean condition to determine, or select, whether or not to run a certain block of statements.

Sequencing

Putting commands in correct order so computers can read the commands.

Pair Programming

A method of programming in which two programmers write code using a single computer. One programmer in the "driver" role uses the mouse and keyboard to actually write the code while a second acts as a "navigator", keeping track of the big picture, catching errors, and making suggestions. Programmers switch roles frequently and communicate throughout the process.

Turtle Programming

a classic method for learning programming with commands to control movement and drawing of an on-screen robot called a "turtle". The turtle hearkens back to early implementations in which children programmed a physical robot whose dome-like shape was reminiscent of a turtle.

Abstraction

a simplified representation of something more complex. Abstractions allow you to hide details to help you manage complexity, focus on relevant concepts, and reason about problems at a higher level.

Function

A named group of programming instructions. Functions are reusable abstractions that reduce the complexity of writing and maintaining programs.

Top Down Design

a problem solving approach (also known as stepwise design) in which you break down a system to gain insight into the sub-systems that make it up.

API

a collection of commands made available to a programmer

Documentation

a description of the behavior of a command, function, library, API, etc.

Hexadecimal

A base-16 number system that uses sixteen distinct symbols 0-9 and A-F to represent numbers from 0 to 15.

Library

a collection of commands / functions, typically with a shared purpose

Parameter

An extra piece of information passed to a function to customize it for a specific need

For Loop

Loops that have a predetermined beginning, end, and increment (step interval).

Loop

The action of doing something over and over again.

Callback function

a function specified as part of an event listener; it is written by the programmer but called by the system as the result of an event trigger.

Event

An action that causes something to happen.

Event-driven program

a program designed to run blocks of code or functions in response to specified events (e.g. a mouse click)

Event handling

an overarching term for the coding tasks involved in making a program respond to events by triggering functions.

Event listener

a command that can be set up to trigger a function when a particular type of event occurs on a particular UI element.

UI Elements

on-screen objects, like buttons, images, text boxes, pull down menus, screens and so on.

User Interface

The visual elements of a program through which a user controls or communicates with the application. Often abbreviated UI.

Debugging

Finding and fixing problems in an algorithm or program.

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"

Expression

Any valid unit of code that resolves to a value.

Variable

A placeholder for a piece of information that can change.

==

The equality operator (sometimes read: "equal equal") is used to compare two values, and returns a Boolean (true/false). Avoid confusion with the assignment operator "=",

Global Variable

A variable whose scope is "global" to the program, it can be used and updated by any part of the code. Its global scope is typically derived from the variable being declared (created) outside of any function, object, or method.

If-Statement

The common programming structure that implements "conditional statements".

Local Variable

A variable with local scope is one that can only be seen, used and updated by code within the same scope. Typically this means the variable was declared (created) inside a function -- includes function parameter variables.

Variable Scope

dictates what portions of the code can "see" or use a variable, typically derived from where the variable was first created. (See Global v. Local)

Concatenate

to link together or join. Typically used when joining together text Strings in programming (e.g. "Hello, "+name)

String

Any sequence of characters between quotation marks (ex: "hello", "42", "this is a string!").

Conditionals

Statements that only run under certain conditions.

Boolean

A single value of either TRUE or FALSE

Boolean Expression

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

!=

Definition: "Is not equal to"

Compares two values - numbers, strings, or other booleans - and returns true if they are not equal, otherwise false.

=

assignment operator

===

a "strict" equality operator - the "triple equal" makes sure that the both the type of data and value are equal. So "3" === 3 is false.

>

Definition: "is greater than"

Compares two values to see if the number on the left is greater than the number on the right.

<

Definition: "is less than"

Compares two values to see if the number on the left is less than the number on the right.

<=

Definition: "is less than or equal to"

Compares two values to see if the number on the left is less than or equal to the number on the right.

>=

Definition: "is greater than or equal to"

Compares two values to see if the number on the left is greater than or equal to the number on the right.

while loop

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

Models and Simulations

a program which replicates or mimics key features of a real world event in order to investigate its behavior without the cost, time, or danger of running an experiment in real life.

Array

A data structure in JavaScript used to represent a list.

List

A generic term for a programming data structure that holds multiple items.