U13.1 data representation Flashcards
1
Q
user defined data type
A
- derived from one or more existing datatypes
- used to extend the built-in datatypes
- programmer’s requirement
2
Q
why are user defined data types necessary
A
- no suitable datatype is provided by the language used
- if a programmer needs a specific datatype
- that meets program requirements
3
Q
non-composite datatype
A
- single datatype that does not refer to another datatype
- e.g: enumerated, pointer, real, string, char, boolean
4
Q
composite datatype
A
- datatype that refers to other datatypes
- data type is constructed from other datatypes
- e.g: record, list, set, array, class, queue, linked list, dictionary
5
Q
record
A
collection of related items which may be of different datatypes
6
Q
list
A
indexed collection that can contain different datatypes
7
Q
set
A
supports mathematical operation
8
Q
class
A
gives properties and methods for an object
9
Q
array
A
collection of items of the same datatype
10
Q
enumerated datatype
A
- non-composite
- defined by a given list of all possible values
- in an order
11
Q
pointer datatype
A
- non-composite
- used to reference a memory location
12
Q
record datatype
A
- composite datatype
- a collection of multiple datatypes
13
Q
declaring a range
A
- 0-89
- DECLARE number : 0..89
14
Q
floating point representation
A
representation of real numbers
15
Q
mantissa
A
the significant digits of floating point number
16
Q
exponent
A
the power of base 2 (that the mantissa is raised to)
17
Q
normalization
A
a technique that is used to make your data more accurate
18
Q
random file
A
- can be read/write at the same time
- contains a collection of data
- normally as records of a fixed length
- can be thought of as having a file pointer that can be moved to any location or address of the file
- record at that location can then be read or written
19
Q
dereferencing
A
getting the value in an address
