Creating an Array: Difference between revisions

 

=={{header|ActionScript}}==

// ActionScript arrays are zero-based

//

var u:Array = [];

var v:Array = [1,2,3];

 

=={{header|Ada}}==

Const : constant Arr := (1 .. 10 => 1, 11 .. 20 => 2, 21 | 22 => 3);

Centered : Arr (-50..50) := (0 => 1, Others => 0);

Ada arrays may be indexed by enumerated types, which are discrete non-numeric types

type Days is (Mon, Tue, Wed, Thu, Fri, Sat, Sun);

type Activities is (Work, Fish);

type Daily_Activities is array(Days) of Activities;

This_Week : Daily_Activities := (Mon..Fri => Work, Others => Fish);

 

=={{header|ALGOL 68}}==

List are mutable arrays. You can put anything into a list, including other lists.

 

empty = []

numbers = [1, 2, 3, 4, 5]

evens = [x for x in range(10) if not x % 2] # same using list comprehension

words = 'perl style'.split()

 

Tuples are immutable arrays. Note that tuples are defined by the "," - the parenthesis are optional (except to disambiguate when creating an empty or single-element tuple):

 

empty = ()

numbers = (1, 2, 3, 4, 5)

zeros = (0,) * 10

anything = (1, 'foo', 2.57, None, zeros)

 

Both lists and tuples can be created from other iterateables:

 

>>> list('abc')

['a', 'b', 'c']

>>> list(open('file'))

['1\n', '2\n', '3\n']

 

Note: In Python 2.6 the ''collections.namedtuple'' factory was added to the standard libraries. This can be used to create classes of lightweight objects (c.f. the Flyweight design pattern) which are tuples that can additionally support named fields.