10 - data types and structures

Question 1

data type

Answer 1

a classification attributed to an item of data, which determines the types of value it can take and how it can be used

Question 2

record

Answer 2

a composite data type
comprising several related items that may be of different data types

Question 3

composite data type

Answer 3

a data type constructed using several of the basic data types available in a particular programming language

Question 4

array

Answer 4

a data structure containing several elements of the same data type
position of each element if found using the index
the first index is the lower bound and the last is the upper
can be 1D or 2D

Question 5

basic/ primitive data types

Answer 5

can be identified by commands in programming languages
boolean
character
date
integer
real
string

Question 6

record data type in pseudocode

Answer 6

TYPE

<typename>
DECLARE <identifier> : <data>
END TYPE
</data></identifier></typename>

Question 7

1D array pseudocode

Answer 7

is like a list
DECLARE <identifier> : ARRAY[LB:UB] OF <data></data></identifier>

Question 8

2D arrays pseudocode

Answer 8

is like a table with rows and columns
DECLARE <identifier> : ARRAY[LB:UB, LB:UB] OF <data></data></identifier>

Question 9

linear search

Answer 9

searches every item in order from the lower bound to the upper

Question 10

linear search pseudocode

Answer 10

INPUT item
foudn <- FALSE
index <- 0
WHILE found = FALSE AND index<= LEN(array)
IF item = array[index]
found = TRUE
index = index + 1
IF found
OUTPUT ‘item found’

Question 11

bubble sort pseudocode

Answer 11

upper = LEN(array)
WHILE swap = FALSE AND upper >0
FOR i <- 0 TO upper - 1
swap = FALSE
IF array[i] > array[i+1]
temp = array[i]
array[i] = array[i +1]
array[i + 1] = temp
swap = TRUE
upper <- upper -1

Question 11

bubble sort

Answer 11

each element is compared with the next and swapped if in the wrong order
this is repeated until the end is reached
this is repeated until the whole list is ordered

Question 12

files

Answer 12

store data
identified by a filename
contain a sequence of characters
can include an end of line character that enables the file to be read from and written to

Question 13

file pseudocode

Answer 13

open file
OPEN <filename> FOR <filemode>
read/ write
READFILE <filename>, <variable>
WRITEFILE ''
to see if the file is at teh end
EOF(<filename>)
when the files not being used
CLOSEFILE < filename ></filename></variable></filename></filemode></filename>

Question 14

ADT

Answer 14

abstract data type
- collect of data and set of operations on that data
eg stack queue linked list

Question 15

stack

Answer 15

a list of several items operating by last in first out - items can be added (push) and removed (pop) - first added is last removed
has a top of stack pointer

Question 16

queue

Answer 16

a list of several items operating on first in first out - items can be added (enqueue) and removed (dequeue)

Question 17

linked list

Answer 17

a list of several items where each item points to the next item
contains pointers and nodes
start pointer points to first element
null pointer signals end eg points to -1

Question 19

file opening mode

Answer 19

READ
WRITE
APPRND - adds data to end

Question 20

how to add/ delete stack

Answer 20

POP from the top of the stack
and PUSH to add to the top of stack

Question 21

how to add/ delete queue

Answer 21

add items to the end (enqueue)
remove items from the front (dequeue)

Question 22

hwo to add / delete linked list

Answer 22

doen need to change the position of any values just edit their pointers

Question 23

declaring a variable of a record type

Answer 23

DECLARE <variable> : <recordtype>
eg DECLARE bibi : person
bibi.name <- “bibi”
bibi.age <- 17</recordtype></variable>