CSC final material

Vocabulary terms and definitions from the Week 2 through Week 12 lecture notes, focusing on hardware, software, MIT App Inventor components, and programming logic.

Computer

A machine that Performs tasks based on a set of Instructions.

Hardware

Physical components of a computer that you can touch, such as a keyboard or mouse.

Software

Non-physical components of a computer that you cannot touch, such as Word or Excel.

Internal Hardware

Hardware located inside the computer, such as $RAM$ and $CPU$.

External Hardware

Hardware located outside the computer, such as a monitor or printer.

CPU

The brain of the computer that handles all thinking and Processing; it is often the most expensive part.

Main Memory

Temporary Storage that holds data only while the computer is turned on.

Secondary Storage

Permanent Storage that retains data even when the computer is turned off.

Input

The act of giving information to the computer, such as through a keyboard or mic.

Output

The process of the computer providing information to you, such as through a display.

4 Major Computer Operations

The sequence of Input, Processing (thinking), Output (display), and Storage (save).

RAM

Random Access Memory; it is temporary and volatile, meaning data is lost once the computer is disconnected.

ROM

Read Only Memory; it is permanent and non-volatile, meaning data stays when the computer is turned off.

System Software

Software that controls hardware and other software resources, such as Windows or macOS.

Application Software

Software that performs specific tasks for the user, such as word processors.

Programming

The art of encoding solutions into instructions that a machine can run to satisfy the user.

Event

An action detected by the computer that causes something to happen.

Internal Event

An event that responds to user interaction from outside the computer, such as a mouse click or button tap.

External Event

An event that responds to a condition inside the Program, such as a timer firing.

Event Handling

The process of responding to an event with a specific action.

Event Handler

A specific block of code written to handle an event when it occurs.

Textbox

A primary method used to capture textual input from a user.

Accelerometer

A hardware device in mobile phones that measures vibration or acceleration motion.

API

Application Programming Interface; a pre-developed set of tools or small programs that interact with code to provide specific services based on set rules.

Peer-Programming

An environment where two programmers share a single workstation.

Driver

The person in peer-programming who writes the code.

Navigator

The person in peer-programming who thinks strategically, reviews code lines, and suggests improvements.

Variables

Data that serves as placeholders for information that can change while the app is running.

Constants

Placeholders for information that cannot change.

Initialize global (name) to (value)

An MIT block that creates a variable with a specific name and starting value.

Get

An MIT block that retrieves the current value of a variable.

Set to

An MIT block that changes or assigns a new value to a variable.

Lifespan of a Variable

The duration changes made to a variable's value last, which is as long as the app is running.

Strings

A sequence of characters surrounded by double quotes.

Identifiers

The practice of choosing clear, purposeful names for variables and components that match their function to ensure code readability.

Initialization

The act of setting the initial starting value of a variable.

Assignment

The act of setting the value stored in a variable's memory space.

Sequencing

Arranging commands in the exact correct order.

Bug

A flaw or part of the program that does not work correctly.

De-bugging

The process of finding and fixing problems in code algorithms.

Clock Component

An internal timer component that fires an event handler block repeatedly at set intervals.

Comments

Descriptive text added by a programmer to explain what code does; it is strictly human-readable and ignored by the computer.

Sprite

A graphic character on a screen with controlled properties defining its location, movement, and visual look.

Behavior

An action a sprite carries out continuously until instructed to stop.

Conditionals

Blocks that evaluate a statement to determine if it is true or false; the action is ignored if the condition is false.

Else block

A block that specifies an alternative action if the primary condition in a conditional fails.

Sprite Collisions

Detected in MIT App Inventor by checking if the rectangular borders of image sprites cross over each other.

Pixels

Tiny individual dots of light on a screen that combine to form an image.

Canvas Coordinates

An $(x,y)$ grid where $X$ is the horizontal position and $Y$ is the vertical position.

Algorithm

A step-by-step list of instructions to complete a task.

Program

An algorithm written in a code language that a machine can run.

Tiny DB Component

A database that saves data permanently on the device so it stays when the app is closed.

Tiny DB Tag

A unique identifier used to store data that acts like a permanent variable name.

List

A data structure that holds multiple items or values at the same time under a single variable name.

Index

The position number of an item in a list; in MIT App Inventor, this always starts at $1$ (not $0$).

Listview Component

A visual screen component used to display a text list on a mobile device.

Selection Index

An internal property of a listview that equals the item's number when tapped by a user.

Default State (Selection Index)

If the user has not clicked anything yet, the Selection Index is $0$.

Notifier Component

A tool used to display pop-up messages, alerts, and warnings on the user's screen.

One-way alert

A notifier that displays text with just one button (like "okay") and does not expect a choice from the user.

Two-way dialog

A notifier that displays a message and expects the user to make a choice by clicking custom buttons.

After Choosing Event

A trigger that occurs when a user clicks a button in a notifier, providing a local variable for use in code.

Code Segmentation

The practice of breaking a large program into separate, organized blocks called Procedures.

Procedure

A reusable block of code written once that can be run anywhere in a program as many times as needed; also known as a function or method.

Simple Procedure

A procedure that runs a sequence of command blocks but does not return a value.

Return Procedure

A procedure that runs a sequence of operations and returns a calculation or value back to the block that called it.

Arguments

Input values passed directly into a procedure so it can perform dynamic calculations.

Loop

The repetition of a block of instructions multiple times to eliminate copied code and save space.

While loop

A loop that repeats instructions as long as a condition is true; it is used when the exact number of runs is unknown.

For loop

A loop that repeats code using a number variable counting from a start value to an end value by a specific step interval.

For each loop

A loop that automatically iterates through every item inside a list one by one without needing a counter.

Infinite loop

A major programming error where a loop repeats forever because the exit condition never becomes false.