AP Computer Science Principles - Big Idea 3

Flashcards for AP Computer Science Principles Big Idea 3: Algorithms and Programming

Variable

An abstraction inside a program that can hold a value. It has associated data storage representing one value at a time, but that value can be a list or other collection that contains multiple values.

Data Types

Represented using variables; include numbers, Booleans, lists, and strings.

Assignment Operator

Allows a program to change the value represented by a variable.

List

An ordered sequence of elements, e.g., [value1, value2, value3, …]

Element

An individual value in a list that is assigned a unique index.

Index

A common method for referencing the elements in a list or string using natural numbers.

String

An ordered sequence of characters.

Data Abstraction

Provides a separation between the abstract properties of a data type and the concrete details of its representation; manages complexity by giving a collection of data a name without referencing specific details.

Algorithm

A finite set of instructions that accomplish a specific task.

Sequencing

The application of each step of an algorithm in the order in which the code statements are given.

Code Statement

A part of program code that expresses an action to be carried out.

Expression

Can consist of a value, a variable, an operator, or a procedure call that returns a value.

Arithmetic Operators

Include addition, subtraction, multiplication, division, and modulus operators.

String Concatenation

Joins together two or more strings end-to-end to make a new string.

Substring

Part of an existing string.

Boolean Value

Either true or false.

Relational Operators

Used to test the relationship between two variables, expressions, or values (=, ≠, >, <, ≥, ≤).

Logical Operators

NOT, AND, and OR, which evaluate to a Boolean value.

Selection

Determines which parts of an algorithm are executed based on a condition being true or false.

Conditional Statements

Or “if-statements,” affect the sequential flow of control by executing different statements based on the value of a Boolean expression.

Nested Conditional Statements

Consist of conditional statements within conditional statements.

Iteration

A repeating portion of an algorithm; repeats a specified number of times or until a given condition is met.

Infinite Loop

Occurs in REPEAT UNTIL iteration when the ending condition will never evaluate to true.

Procedure

A named group of programming instructions that may have parameters and return values (also referred to as method or function).

Parameters

Input variables of a procedure.

Arguments

Specify the values of the parameters when a procedure is called.

Procedural Abstraction

Provides a name for a process and allows a procedure to be used only knowing what it does, not how it does it.

Modularity

The subdivision of a computer program into separate subprograms.

Software Library

Contains procedures that may be used in creating new programs.

Simulation

Abstractions of more complex objects or phenomena for a specific purpose.