Global Variable – a variable that can be accessed by all modules and functions at any time. It is not confined to a single block. Global variables are commonly kept to a minimum because the more there are bug isolation is more difficult.
Local Variable – a variable that is confined to a single block. Local variables are only accessible from the function or block of which it is declared to.
Elementary Data Types
•Character – a single byte of information, either a single letter, number, or symbol
•String – a contiguous set of alphanumeric data that doesn’t contain numbers
used for calculations
•Integer
- a whole number or natural number, not a decimal or fraction
•Floating
- a number whose decimal can be placed anywhere relative to the
significant digits of that number
•Boolean
- a yes or no, true or false
Data Identifier (name) – a name that is assigned to a field or variable that identifies your data.
Its Data Type – part of a data identifier that classifies or identifies what type of data that various data is.
Its Memory Address – an identifier for a memory location. It relates the exact place in a computers memory that certain data is stored.
The Actual Data – is the data that can be manipulated depending on its type. It is what all pointers point to.
A Variable – A symbolic name given to a value that can be changed or modified.
Literal – any data that is typed by a programmer and remains unchanged when translated into machine code. An example would be a text message displayed on the screen or a constant numerical value used for calculation purposes.
Constant – any fixed value in a program such as error messages, dates, minimum and maximum amounts, etc.
Number Base Systems – a way to represent numbers where the base is the total amount of unique symbols used to represent numbers.
BASE 2 – A number system also known as binary. It is “based” on two “numbers” or electrical states (on and off). It is what every computers uses to operate, internally.
BASE 10 – A number system consisting of 10 digits (0, 1, 2 , 3, 4, 5, 6, 7, 8, 9). It is the most widely used numerical system by modern civilizations. Also known as decimal.
BASE 16 – A number system based on 16 numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) and (A, B, C, D, E, F) made to represent numbers 10-15. Also known as Hexadecimal.
Floating Point – A method for storing and calculating numbers where the significant digits are stored in a separate place as the location of the radix or decimal point.
Decimal Data Representation – An exact type of numerical data that can hold a maximum of 38 digits, with the radix in any position
Direct Addressing - A memory address pertaining to data that directly identifies the storage location without using an intermediate reference.
Relative Addressing – A memory address pertaining to data that represents some distance from the base address.
Data Types and Data Abstraction – Data abstraction allows the handling of data bits in meaningful ways and is the basic motivation behind data type. Data abstraction is a focused representation of an item or items.
•File
- a common denominator of storage containing a collection of bytes stored as an individual entity.
•Record
- a group of related fields that store data about a subject. A collection of records makes up a file.
•Array
- an arrangement of data elements in a particular order. An array can hold multiple variables.
1.Single Dimension
- also known as a vector, a vector array is like a list.
2.Multi dimension
- also known as a matrix, a matrix array arranges elements in a row and column form
Language Statements – a statement is the smallest element of imperative programming languages. Imperative programming languages use a sequence of one or more statements to form a program.
A. Natural Language Statements/Grammar and Logic
- statements using a natural language (a human language)
B. Artificial Language Statements/Syntax and Semantics
- statements using symbols that correspond to instructions in a programming language
C. Input/Output Statements
- a statement telling the computer where the input is coming from how to compute it and where to send the output
D. Assignment Statements
- used to assign a value to a variable
E. Program Design Language (PDL) - Meta Language
- a language used to make a statement about a statement in another language.
1.Syntax Diagrams
- a diagram that explains how the syntax of a language is used, each diagram has a beginning and end point, and shows all possible paths between these two points.
2.BNF
(Backus-Naur Form)- A notation technique used to describe the syntax of a language, mostly for exact descriptions of languages, probably used in the language’s manual.
F. Elementary Language Statements and Structured Language Statement
- elementary language statements are statements in a programming language at a basic level. Structured language statements are statements that are paired together in order to minimize error.
1.Assignment and Unconditional Statements
- Assignment and Unconditional statements are statements that produce the same result unconditionally.
2.Selection and Looping Statement
- a selection statement is a statement that chooses to perform different actions or to perform no action, depending on the data it’s given. A looping statement will repeatedly perform an action if the statement remains true, once the statement is false the action ceases.
Expressions Components – parts of a expression which include specific values, constants, variables, operators, and functions
A. Operators, Operands and Results
- operators specify what operation to perform. Operands specify what data is to be manipulated. Results are what you get when operands are manipulated by operators.
1.Unary
- when one operand is manipulated by and operator
2.Binary
- when two operands are manipulated by an operator
B. Simple Types
1.Arithmetic
- using numerical values
2.Logical
- using mathematical logic
3.Relational – uses a model such as a spreadsheet to relate data
C. Result
1.Unconditional (Not Boolean)
- any result besides true or false
2.Conditional (Boolean)
- A result of true or false
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