[Week 3] Fundamentals of Programming

Variables

Named memory locations holding varying contents over time.

Constants

Values that do not change during program execution.

Data Types

Classifications describing values, storage, and operations on data items.

Numeric Data

Consists of numbers, possibly with decimals or signs.

String Data

Nonnumeric data items used in text processing.

Unnamed Constants

Values without identifiers like variables.

Declaration

Statement specifying data type, identifier, and optionally, initial value for a variable.

Type-Safety

Feature in some languages preventing incorrect data type assignments.

Identifier

Name chosen by the programmer for a program component.

Type-Specific Variables

Variables intended for numeric or string data.

Variable

Named memory locations holding changing values for calculations.

String Constants

Alphanumeric values enclosed in quotation marks.

Numeric Constants

Numbers that remain constant during program execution.

Memory Storage

Location where data items are stored for processing.

Data Type Classification

Description of values, storage, and operations for a data item.

Variable Declaration

is a statement that reserves a named memory location and includes a data type, an identifier, an optional assignment operator and assigned value, and an ending semicolon.

Type-Safe Languages

Languages preventing incorrect data type assignments.

Identifier Naming Rules

Guidelines for creating names for program components.

Type-Safe Data Assignment

Assigning data items to variables of correct data type.

Variable Identifier

Name associated with a specific memory address in a program.

Variable Declaration Components

These are components that include data type, identifier, and optional initial value in a variable statement.

Numeric Variable

Variable intended to hold numerical values for arithmetic operations.

String Variable

Variable holding text and special characters, not intended for arithmetic operations.

Reserved Keywords

Words not allowed as variable names due to language syntax

Variable Name Length

Limits vary; newer languages often allow virtually unlimited lengths

Case Sensitivity

Identifiers differ based on case in modern languages

Variable Naming Conventions

Consistent naming improves program readability

Variable Naming Rules

1. One word only, 2. Starts with a letter, 3. Meaningful

Identifier Clarity

Descriptive names aid program comprehension and maintenance

Variables

are named memory locations

Assignment Operator

Symbol for assigning values; always operates from right to left, which means that it has right-associativity or right-to-left associativity

Binary Operator

Requires two operands for operation

Lvalue

Result to the left of an assignment operator; always a memory address

Initializing Variables

Assigning a starting value to a declared variable

Garbage Value

Unknown value in an uninitialized variable

Named Constant

Values assigned once and remain constant throughout the program

Named Constant

A constant variable with a recognizable identifier and unchangeable value

Magic Number

An unnamed constant with unclear purpose, like 0.06

Arithmetic Operators

Symbols used in programming to perform mathematical operations

Precedence

Order in which operations are carried out in an arithmetic statement

Associativity

Direction in which operations with the same precedence are evaluated

Integer Data Type

Numeric data type for whole numbers in programming

Floating-Point Data Type

Numeric data type for numbers with decimal places in programming

Unary Operator

Operator that requires only one operand

Literal

Directly written value in code, like 0.06

Program Translation

Process of converting code into machine language

Program Maintenance

Process of updating and managing a program over time

Machine Language

Low-level language directly understood by a computer

Expression

A combination of variables, operators, and values that represents a single result value.

Parentheses

Symbols used to group expressions and control the order of operations

Conversion

Process of changing data from one type to another

Logical Error

Error in program logic that causes unexpected behavior

Binary Number System

Number system with base 2, using 0s and 1s

Decimal Number System

Number system with base 10, using digits 0-9

Hexadecimal Number System

Number system with base 16, using digits 0-9 and A-F

Octal Number System

Number system with base 8, using digits 0-7

Bitwise Operator

Operator that performs operations on individual bits

Truncated

Decimal portion of the result is cut off

Modulo Operator

Returns the remainder after division of two integers

Even Number

Number with a remainder of 0 when divided by 2

Odd Number

Number with a remainder of 1 when divided by 2

Module

Smaller unit in programming, like subroutine or function

Abstraction

Process of focusing on important properties, ignoring details

Functional Decomposition

Breaking down a program into modules

Main Program

Executes modules by calling them

Modularization

Breaking down a program into modules

Abstraction

Enables focusing on important details, ignoring nonessential

High-Level Programming Languages

Uses English-like vocabulary, abstracting low-level details

ComputeFederalWithholdingTax()

Example of a module name for a payroll program

Reusability

Ability to use modules in multiple programs

Reliability

Assurance that a module functions correctly

Stand-Alone Modules

Functional components that can be used independently

Mainline Logic

Basic steps in the main program of a software

Module Header

Includes module identifier and necessary identifying information

Module Body

Contains all statements in the module

Return Statement

Marks the end of the module and identifies the point of control return

Module Naming

Follows rules similar to variable naming, often with parentheses

Chained Calls

Modules calling other modules in a sequence

Flowchart Symbol

Rectangle with a bar across the top used to call a module

Encapsulation

Containing instructions within a module

Functional Cohesion

Degree to which statements in a module contribute to the same task

Local Variables

Declared within a module and usable only within that module

Global Variables

Declared at the program level and known to the entire program

Housekeeping Tasks

Initial steps in a program like variable declarations and displaying instructions

Detail Loop Tasks

Core work of the program executed repeatedly for each set of input data

End-of-Job Tasks

Steps taken at the end of the program to finish the application