Introduction to Computer Science Section 1

Abstract Data Type

A blueprint for organizing and working with data that defines what operations can be performed on the data without specifying how they are implemented

Array

A collection of items stored in a contiguous memory block, each identified by an index number, allowing for efficient access to elements based on their position

Composite Variable

A variable that can hold multiple pieces of data, often grouped together under a single name

Container

A data structure that holds a collection of elements, providing methods to add, remove, and access items within it

Data Structure

A way of organizing and storing data in a computer's memory designed to facilitate the efficient retrieval, insertion, and deletion of data

Linked List

A sequence of elements where each element points to the next one, forming a chain

Linked Structure

Any structure composed of elements connected by links or pointers, enabling dynamic relationships among data elements

List

A collection of items arranged in a linear sequence, allowing for easy access to and the insertion and deletion of elements

Queue

A data structure that follows a first-in, first-out (FIFO) order where elements are added to the back and removed from the front

Record

A data structure that groups related pieces of information under a single name, typically consisting of multiple fields or attributes

Stack

A data structure that follows a last-in, first-out (LIFO) order where elements are added and removed from the same end, known as the top

argument

the actual value or data you pass to a function or subprogram when you call it

parameter

a variable in a function or subprogram definition that acts as a placeholder for the value (argument) you pass when you call the function

parameter list

a set of parameters defined in a function or subprogram specifying the number and types of inputs the function can accept

reference parameter

a type of parameter that allows a function to modify the actual variable passed to it

subprogram (function)

a general term for a block of code that performs a specific task and can be reused

value parameter

a type of parameter that passes a copy of the argument's value to the function

asynchronous

a type of operation that runs independently of the main program flow, allowing additional tasks to happen without waiting for others to complete

bytecode

a low-level, platform-independent code that is executed by a virtual machine, typically produced by compiling source code

case sensitive

when a programming language treats uppercase and lowercase letters as different characters

class

a blueprint for creating objects in object-oriented programming that defines the properties and behaviors the objects will have

compiler

a tool that translates source code written in a high-level programming language into machine code or bytecode that a computer can execute

encapsulation

bundling data and methods that operate on the data into a single unit (a class) and restricting access to some of the object's components

field

a variable associated with a class or object that represents a piece of data stored in that object

inheritance

the creation of a new class based on an existing class, inheriting its properties and methods while adding new ones or modifying existing ones

instantiate

the process of creating a specific instance of a class, resulting in an object

interpreter

a tool that executes source code directly and translates it into machine code in real time rather than compiling it before

method

a function defined within a class that describes the behaviors or actions an object can perform

object

an instance of a class containing data and methods defined by the class, representing a specific entity in a program

paradigm

a style or approach to programming—such as object-oriented, procedural, or functional programming—that dictates how code is structured and organized

polymorphism

a concept that allows objects of different classes to be treated as objects of a common superclass

strong typing

a feature in which each variable has a specific type and you must follow strict rules about how types are used and combined, helping prevent errors in your code

analog data

data represented in a continuous and variable form

American Standard Code for Information Interchange (ASCII)

a standard encoding system for text characters that uses numeric values to represent letters, numbers, and symbols

bandwidth

the maximum rate of data transfer across a network or communication channel, usually measured in bits per second

binary

a numerical system that uses only two digits, zero and one, to represent data in computing

Boolean expression

a logical statement that can only be true or false and uses operators like AND, OR, and NOT

character

a single letter, digit, or symbol used in writing text

character set

a collection of characters that a computer can recognize and process, like ASCII or Unicode compression ratio: the ratio of the original data size to the compressed data size, indicating how much the data has been reduced

control structure

constructs in programming that control the flow of execution, such as loops and conditional statements

data

raw facts and figures that can be processed to produce meaningful information

data compression

the process of reducing the size of data to save space or transmission time

data types

categories of data that define what kind of value can be stored, like integers, floats, and strings, and how it can be used

declaration

a statement in programming that specifies the name and type of a variable or function without assigning a value

digital data

data represented using discrete binary values (zeroes and ones)

floating point

a way to represent real numbers that can have fractional parts using a format that includes a base and an exponent

Huffman encoding

a compression technique that uses variable-length codes for data representation based on frequency of occurrence

information

data that have been processed or organized in a meaningful way to be useful

integer

a whole number

keyword encoding

a method of data compression that replaces frequently occurring patterns with shorter codes

lossless

a type of data compression where no information is lost and the original data can be perfectly reconstructed

lossy

a type of data compression that reduces file size by permanently eliminating some information, which may affect quality

numeric

any value that is a number

overflow

a condition in which a calculation exceeds the maximum value that can be represented within a given number of bits

pulse-code modulation (PCM)

a method used to digitally represent analog signals

radix point

the decimal point in a number system that indicates the separation between integer and fractional parts

real

a data type representing numbers that can have fractional parts, often called floating-point numbers

reclocking

the process of refreshing the timing signals in digital data to ensure accuracy and synchronization

run-length encoding

a simple compression technique that replaces sequences of repeated characters with a single character and a count

scientific notation

a method of representing very large or very small numbers by using powers of 10

signed-magnitude representation

a way of encoding positive and negative numbers where one bit represents the sign and the remaining bits represent the magnitude

string

a sequence of characters treated as a single data element and used for text manipulation

strong typing

a feature in programming languages where each variable is explicitly declared to be of a specific type, reducing errors

ten's complement

a mathematical method for representing negative numbers in a decimal system

Unicode

a universal character set that includes characters from virtually all writing systems, allowing for consistent encoding and representation of text globally

alphanumeric values

characters that include both letters (A-Z) and numbers (0-9)

assignment operator

a symbol used to assign a value to a variable, typically =

assignment statement

a line of code that assigns a value to a variable, like x = 5

binary operator

an operator that takes two operands, such as +, -, *, and /

camel casing

a naming convention where the first letter is lowercase and each subsequent word starts with an uppercase letter, like myVariableName

garbage

unused or leftover data in memory that the program no longer needs or references

Hungarian notation

a naming convention where the name of a variable starts with a prefix indicating its type, like strName for a string variable

identifier

a name given to a variable, function, or other item in code to identify it

initializing a variable

assigning an initial value to a variable when it is declared, like int x = 10

kebob case

a naming convention where words are all lowercase and separated by hyphens, like my-variable-name

keyword (reserved word)

a reserved word in a programming language that has a specific meaning and cannot be used as an identifier, like if, while, and class

lvalue

an expression that refers to a memory location, which can appear on the left side of an assignment, like x in x = 5

mixed case with underscores

a naming convention that combines uppercase and lowercase letters with underscores between words, like My_Variable_Name

numeric constant

a fixed number value written directly in the code, like 42

numeric variable

a variable that holds a number value

operand

a value or variable on which an operator acts, like 3 and 5 in 3 + 5

Pascal casing

a naming convention in which each word in the name starts with an uppercase letter, like MyVariableName

right-to-left associativity

the order in which operations are performed in expressions where operators of the same precedence appear, processed from right to left

snake casing

a naming convention in which words are all lowercase and separated by underscores, like my_variable_name

string constant

a fixed sequence of characters written directly in the code, like "Hello, World!"

string variable

a variable that holds a sequence of characters (a string)

type safety

ensuring a variable is only used in ways consistent with its data type, preventing type errors

unnamed constant

a fixed value used directly in code without assigning it to a variable, also known as a magic number, like 3.14 for π

variable

a named storage location in memory that can hold different values throughout a program

abstract step

a high-level action in an algorithm that describes what needs to be done without detailing how to do it

algorithm

a step-by-step set of instructions designed to perform a specific task or solve a problem

branch

a point in an algorithm where a decision is made, leading to different actions based on conditions (e.g., if-then statements)

infinite loop

a loop that never ends because the termination condition is never met or is incorrectly written

input

data that are provided to a program for processing

loop control variable

a variable that determines whether the loop will continue running or stop, often incremented or modified within the loop

nested structure

a programming construct where one control structure (like a loop or a conditional statement) is placed inside another

output

data that are produced by a program and presented to the user or another system

pretest loop

a loop that evaluates its condition before executing the body of the loop, such as a while loop

pseudocode

A simplified, human-readable version of a program's code that outlines the logic without strict syntax rules

repetition (iteration)

the act of executing a set of instructions multiple times, typically using loops