AP Computer Science Key Terms

variable

a named storage location that holds changeable data

data type

a classification of data such as integer, string, float, or boolean

integer

a whole number

float

a number with a decimal point

list

a collection of elements stored in a single variablei

index

the position of an element in a list, usually starting 0

element

an individual item in a list

data abstraction

managing complexity by using data structures to represent information

bit

a single binary digit (0 or 1)

byte

a group of 8 bits

binary number system

base 2 number system, 0s and 1s

overflow error

when a number is too large to be represented with the available bits

round-off error

when the computer rounds a value that is different from the exact value since it cannot be stored with the available memory

lossy compression

reduces file size by permanently removing some data

audio, video, & pictures

What do you use lossy compression for?

loseless compression

reduces file size without losing any data

text, zip, and high quality files

What do you use lossless compression for?

metadata

data that describes other data

creation date, author, file format, file size, etc

What is included in metadata?

Algorithm

a fine set of step-by-step instructions designed to accomplish a specific task

sequencing

executing instructions in a specific order

selection

using conditional statements to choose different outputs

iteration

repeating a set of instructions using loops

condition

a boolean expression that is true or false

boolean

a data type that can only have two values: true or false

expression

a combination of variables, values, and operators that evaluates to a value

procedure/function

a named set of instructions that preforms a specific task

parameter

a variable in a function definition that receives a value

argument

the actual value passed through a function when it is called

return value

the value a function sends back to the part of the program that called it

abstraction

reducing complexity by focusing on relevant details/generalizing a program

procedural abstraction

using functions to hide the details of how a task is performed

implementation

the actual code that carries out an algorithm