Chapter 3

multinational character

Modified Latin characters used by western European languages other than English; such as á , ç , and ü

octal notation

a base-8 numbering system that uses digits from 0 to 7

underflow

a condition that occurs when a value is to small to represent in floating point notation; also refers to overflow of a negative exponent in floating point notation

pointer

a data element containing the address of another data element; typically used in data structures; also a synonym for cursor in a display device

double-precision

a data format that combines two adjacent fixed-length data items to hold a single value; increases accuracy or numeric range

record

a data structure composed of other data structures or primitive data elements; commonly used as a unit of input and output to and from files or databases

class

a data structure containing both traditional (static) data elements and programs that manipulate data; it combines related data items in much the same way a record does, but it extends a record to include methods for manipulating data items

singly linked list

a data structure in which each list element contains a pointer to the next list element

doubly linked list

a data structure in which each list element contains pointers to both the previous and the next list elements

linked list

a data structure that uses pointers so that the list element can be scattered among non-sequential storage locations

Boolean data type

a data type that can store only the value true or false; requires only a single bit for storage

unsigned integer

a data type that stores positive values as ordinary binary numbers; its value is always assumed to be positive

Boolean logic

a formal logic system in which statements can be evaluated only as true or false; well suited to the binary numbers used in computer processing

excess notation

a format that can be used to represent signed integers with a fixed number of bits; essentially it divides a range of ordinary binary numbers in half and uses the lower half for negative values and the upper half for non-negative values

bit string

a group of bits that describe a single data value

floating-point notation

a method for representing real numbers that consists of two parts: a mantissa and an exponent; the mantissa holds the bits that are interpreted to derive the real number's digits, and the exponent value indicates the radix point's position

base

a multiplier that describes the difference between one position and the next in a numbering system also know as radix

twos complement notation

a notation system that represents positive integers as ordinary binary values and negative integers by adding 1 to the complement of the positive value

binary number

a number in which each digit can have only one of two possible values (1 or 0)

real number

a number that can contain both whole and fractional components; the fractional components is represented by digits to the right of the radix point

hexadecimal notation

a numbering system with a base value of 16; uses digits from 0-9 and letters from A-F, which represent the decimal values 10 to 15

data structure

a related group of primitive data elements organized for some type of common processing; its defined and manipulated in software because the CPU cant manipulate data structures directly

string

a sequence of characters forming a meaningful word, phrase or other useful group

file

a sequence of records on secondary storage; the common organization schemes for files are sequential and indexed

Unicode

a standard 16-bit or 32-bit character -coding method that assigns non-negative integers to represent printable characters; includes alphabets, ideographs, and characters for most of the world's languages

American Standard Code for Information Interchange (ASCII)

a standard 7-bit coding method for character data and some control codes

byte

a string of 8 bits; generally the smallest unit of data that can be read from or written to a storage device

character

a symbol in written language including letters, numerals, and punctuation marks

integer

a whole number that is, a value that doesn't have a fractional part

Extended Binary Coded Decimal Interchange Code (EBCDIC)

an IBM mainframe coding method for representing character data in a 8-bit format

Latin-1

an ISO standard character- coding table containing ASCII-7 characters in the lower 128 table entries and most of the characters used by Western European languages in the upper 128 table entries

segmented memory model

an approach to assigning memory address in which primary storage is divided into equal-sized segments called pages, identified by sequential non-negative integers; each byte of memory has a two part address: the first part identifies the page, and the second part identifies the byte in the page

flat memory model

an approach to assigning memory addresses inn which memory addresses in which memory locations are described by single unsigned integers corresponding to linear positions

overflow

an error that occurs when the result of a processing operation exceeds the format's numeric range

signed integer

an integer that uses a sign bit to indicate whether it is a negative or positive

International Organization for Standardization (ISO)

an international group with functions similar to those of the American National Standards institute

array

an ordered list of data elements, in which each element can be referenced by an index to its position; array elements are normally referenced by array name and index value

bit

derived from the term binary digit, it represents one digit of a binary number and can have the value (1 or 0)

long integer

double-precision representation of integers

manipulation

in computer processing, refers to working with data by executing processor instructions, such as addiction, subtraction, and equality comparisons

index

in file organization, an array of pointers to records

radix point

in numbering systems other than decimal, the period or comma that separates the whole and fractional parts of a numeric value

object

one instance, or variable of a class

method

programs for manipulating data items in a class

truncation

the act of deleting bits that don't fit in a storage location

primitive data type

the integer, real number, character, Boolean, and memory address data types that CPU's can manipulate directly

International Alphabet 5 (IA5)

the international equivalent of the ASCII coding method for character data

most significant digit

the left most digit in a bit string that holds the greatest weight; also known as high-order bit

address

the location of a data element in a storage device; often used in data structures

decimal point

the period or comma in the decimal numbering system that separates the whole number and fractional parts of a numeric value

least significant digit

the rightmost digit in a bit string that represent the lowest weight also known as low-order bit

numeric range

the set of all data values that can be represented by a data- encoding method

collating sequence

the specific order for assigning numeric codes to characters or symbols