Arrays

Declare a 1D array

DECLARE FirstNames : ARRAY[1:5] OF STRING

Declare a 2D array

DECLARE FullNames : ARRAY[1:5, 1:2] OF STRING

• Declare row first

Array benefits

• Values can be accessed through a loop-controlled variable

• Easy to design, test and code

• Multiple instances only need to reference one identifier

Term for minimum and maximum values an array can take

Lower bound, upper bound

Term for the variable n in the pseudocode expression

Index

Declaring membership array of type student

DECLARE Membership : ARRAY[1:3000} OF Student

Efficient bubble sort (ascending) - 2D array, 1000 students and their corresponding marks

PROCEDURE Sort()

….DECLARE Temp : INTEGER

….DECLARE NoSwaps : BOOLEAN

….DECLARE Boundary, Row, Col : INTEGER

….Boundary ← 999

….REPEAT

……..NoSwaps ← TRUE

……..FOR Row ← 1 TO Boundary

…………IF Result[Row, 2] > Result[Row + 1, 2] THEN

…………….FOR Col ← 1 TO 2

………………..Temp ← Result[Row, Col]

………………..Result[Row, Col] ← Result[Row + 1, Col]

………………..Result[Row + 1, Col] ← Temp

…………….NEXT Col

…………….NoSwaps ← FALSE

…………ENDIF

……..NEXT Row

……..Boundary ← Boundary - 1

….UNTIL NoSwaps = TRUE

ENDPROCEDURE

“Benefits of arrays”

• Multiple instances reference single identifier, fewer identifiers needed

• Easier to process/search - array can be iterated through

• Makes the program easier to write / debug

“State three benefits of using an array of records to store data”

• Allows for iteration, can use a loop to access records

• Use of index to directly access a record in the array

• Simplifies the code, reduces duplication // program easier to write

Uses and benefits of arrays

• Simplify an algorithm, makes it easier to amend or add data

• Are easier to understand, test and debug

• It is possible to iterate through the values using a loop - make data organisation easier

• Arrays of records can store multiple data types