Array

An ADT that contains a collection of items (normally primitive data types), each identified by at least one array index.

Properties

• immutable length
  • in other words, has a fixed length and cannot be changed after initialisation
  • this also means by “adding” an element into an array, you are overwriting it at its specific array index
• elements are accessed using 0-based indexing
  • this means that the first element has index 0
• elements are ordered

Signature

name: Array
import: element, integer, boolean
operations:
  newArray: integer -> Array;
  get: Array × integer -> element;
  set: Array × element × integer -> Array;
  length: Array -> int;

Implementation

Python 3

# initialisation
car_brands = ["bmw", "mercedes", "toyota"]
 
# getting
car_brands[1] # "mercedes"
 
# setting
car_brands[0] = "volvo" # ["kia", "mercedes", "toyota"]
 
# length
len(car_brands) # 3