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{{task}}
{{DeprecatedTask}}
'''Please do not add new code, and merge existing code to the [[Arrays]] task.'''
This task is about [[numeric arrays]]. For '''hashes''' or '''associative arrays''', please see [[Creating an Associative Array]].


This task is about numerically-indexed arrays. For '''hashes''' or '''associative arrays''', please see [[Creating an Associative Array]].
In this task, the goal is to create an [[array]]. Mention if the [[array base]] begins at a number other than zero.


In this task, the goal is to create an [[array]]. Mention if the [[array base]] begins at a number other than zero.
==[[ActionScript]]==
In addition, demonstrate how to initialize an array variable with data.
[[Category:ActionScript]]
// ActionScript arrays are zero-based
//
// creates an empty array
var arr1:Array = new Array();
// creates an array with 3 numerical values
var arr2:Array = new Array(1,2,3);
//
// or just use the shorthand
var u:Array = [];
var v:Array = [1,2,3];

==[[Ada]]==
[[Category:Ada]]
'''Compiler:''' GCC 4.1.2

Ada array indices may begin at any value, not just 0 or 1
type Arr is array (Integer range <>) of Integer;
Uninitialized : Arr (1 .. 10);
Initialized_1 : Arr (1 .. 20) := (others => 1);
Initialized_2 : Arr := (1 .. 30 => 2);
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);

==[[AppleScript]]==
[[Category:AppleScript]]

AppleScript arrays are called lists:
set empty to {}
set ints to {1, 2, 3}

Lists can contain any objects including other lists:
set any to {1, "foo", 2.57, missing value, ints}

==[[BASIC]]==
[[Category:BASIC]]
'''Interpeter:''' [[QuickBasic]] 4.5, PB 7.1

REM Force index to start at 1..n
OPTION BASE 1

REM Force index to start at 0..n
OPTION BASE 0

REM Specify that the array is dynamic and not static
'$DYNAMIC
DIM SHARED myArray(-10 TO 10, 10 TO 30) AS STRING
REDIM SHARED myArray(20, 20) AS STRING
myArray(1,1) = "Item1"
myArray(1,2) = "Item2"

==[[C]]==
[[Category:C]]
'''Compiler:''' GCC, MSVC, BCC, Watcom

'''Libraries:''' Standard
Dynamic
#include <stdlib.h> /* for malloc */
#include <string.h> /* for memset */
int n = 10 * sizeof(int);
int *myArray = (int*)malloc(n);
if(myArray != NULL)
{
memset(myArray, 0, n);
myArray[0] = 1;
myArray[1] = 2;
free(myArray);
myArray = NULL;
}

Static

int myArray2[10] = { 1, 2, 0}; /* 3..9 := 0 */

==[[C plus plus|C ]]==
[[Category:C plus plus]]
'''Compiler:''' [[GCC]], [[Visual C plus plus|Visual C ]], [[BCC]], [[Watcom]]


Using dynamically-allocated memory:
const int n = 10;
int* myArray = new int[n];
if(myArray != NULL)
{
myArray[0] = 1;
myArray[1] = 2;
delete[] myArray;
myArray = NULL;
}

Using fixed memory:
int myArray2[10] = { 1, 2, 0}; /* 3..9 := 0 */

'''Libraries:''' [[STL]]
// STL
std::vector<int> myArray3(10);
myArray3.push_back(1);
myArray3.push_back(2);

'''Libraries:''' [[Qt]]
// Qt
QVector<int> myArray4(10);
myArray4.push_back(1);
myArray4.push_back(2);

'''Libraries:''' [[Microsoft Foundation Classes]]
// MFC
CArray<int,int> myArray5(10);
myArray5.Add(1);
myArray5.Add(2);

==[[C sharp|C#]]==
[[Category:C sharp]]
Example of array of 10 int types:

int[] numbers = new int[10];

Example of array of 3 string types:

string[] words = { "these", "are", "arrays" };

You can also declare the size of the array and initialize the values at the same time:

int[] more_numbers = new int[3]{ 21, 14 ,63 };


For Multi-Deminsional arrays you declare them the same except for a comma in the type declaration.

The following creates a 3x2 int matrix
int[,] number_matrix = new int[3,2];

As with the previous examples you can also initialize the values of the array, the only difference being each row in the matrix must be enclosed in its own braces.

string[,] string_matrix = { {"I","swam"}, {"in","the"}, {"freezing","water"} };

or

string[,] funny_matrix = new string[2,2]{ {"clowns", "are"} , {"not", "funny"} };

==[[Clean]]==
[[Category:Clean]]
Array denotations are overloaded in Clean, therefore we explicitly specify the types. There are lazy, strict, and unboxed array.
===Lazy array===
Create a lazy array of strings using an array denotation.
array :: {String}
array = {"Hello", "World"}
Create a lazy array of floating point values by sharing a single element.
array :: {Real}
array = createArray 10 3.1415
Create a lazy array of integers using an array (and also a list) comprehension.
array :: {Int}
array = {x \\ x <- [1 .. 10]}
===Strict array===
Create a strict array of integers.
array :: {!Int}
array = {x \\ x <- [1 .. 10]}
===Unboxed array===
Create an unboxed array of characters, also known as <tt>String</tt>.
array :: {#Char}
array = {x \\ x <- ['a' .. 'z']}

==[[ColdFusion]]==
[[Category:ColdFusion]]
Creates a one-dimensional Array
<cfset arr1 = ArrayNew(1)>
Creates a two-dimensional Array in CFScript
<cfscript>
arr2 = ArrayNew(2);
</cfscript>
''ColdFusion Arrays are '''NOT''' zero-based, they begin at index '''1'''''

==[[Common Lisp]]==
[[Category:Common Lisp]]
Creates a one-dimensional array of length 10. The initial contents are undefined.
(make-array 10)
Creates a two-dimensional array with dimensions 10x20.
(make-array '(10 20))
<tt>make-array</tt> may be called with a number of optional arguments.
(make-array 4 :element-type 'integer :initial-contents '(1 2 3 4) :adjustable t)

==[[D]]==
[[Category:D]]
'''Compiler:''' [[DMD]],[[GDC]]

// dynamic array
int[] numbers = new int[5];
// static array
int[5] = [0,1,2,3,4];

==[[E]]==
[[Category:E]]

[] # immutable, empty
[1,9,17] # immutable, 3 elements
[].diverge() # mutable, empty
[].diverge(int) # mutable, integers only

==[[Forth]]==
[[Category:Forth]]

Forth has a variety of ways to allocate arrays of data, though it has no built-in array handling words, favoring pointer manipulation.

Static array of 200 cells, uninitialized:

create MyArray 200 cells allot
here MyArray - cell / constant MyArraySize

Static array containing the numbers 1 to 5

create MyArray 1 , 2 , 3 , 4 , 5 ,
here MyArray - cell / constant MyArraySize

Dynamic array allocation:
0 value MyArray
200 cells allocate throw to MyArray

Dynamic array free:
MyArray free throw
0 to MyArray

==[[Fortran]]==
[[Category:Fortran]]

Default case:

integer a(10)

this will have ten elements. Counting starts at 1. If a zero-based array is needed, declare like this:

integer a(0:9)

this mechanism can be extended to any numerical indices, and allowed number of dimensions (and of course to other data types than integers). For example

real*8 (25:29,12)

will be an two-dimensional, 5x12-array of 8-byte floats, where the first dimension can be addressed numerically as 25, 26, 27, 28 or 29 (and the second dimension as 1 .. 12).


==[[IDL]]==
[[Category:IDL]]

IDL doesn't really distinguish between scalars and arrays - the same operations that can create the one can <i>usually</i> create the other as well.

a = 3
help,a
A INT = 3
print,a^2
9

a = [3,5,8,7]
help,a
A INT = Array[4]
print,a^2
9 25 64 49

==[[Java]]==
[[Category:Java]]
For example for an array of 10 int values:
int[] intArray = new int[10];

Creating an array of Strings:

String[] s = {"hello" , "World" };

==[[JavaScript]]==
[[Category:JavaScript]]
var myArray = new Array();
var myArray2 = new Array("Item1","Item2");
var myArray3 = ["Item1", "Item2"];

=={{header|LSE64}}==
10 myArray :array

==[[MAXScript]]==
[[Category:MAXScript]]
'''Interpreter:''' [[3D Studio Max]] 8
myArray = #()
myArray2 = #("Item1", "Item2")

==[[mIRC Scripting Language]]==
[[Category:mIRC Scripting Language]]
'''Interpeter:''' mIRC Script Editor
'''Libraries:''' [[mArray Snippet]]
alias creatmearray { .echo -a $array_create(MyArray, 5, 10) }

==[[OCaml]]==
[[Category:OCaml]]
Using an array literal:

let array = [| 1; 2; 3; 4; 5 |];;

To create an array of five elements with the value 0:

let num_items = 5 and initial_value = 0;;
let array = Array.make num_items initial_value

To create an array with contents defined by passing each index to a callback (in this example, the array is set to the squares of the numbers 0 through 4):

let callback index = index * index;;
let array = Array.init 5 callback


==[[Perl]]==
[[Category:Perl]]
'''Interpreter:''' [[Perl]] 5

my @empty;
my @empty_too = ();

my @populated = ('This', 'That', 'And', 'The', 'Other');
print $populated[2];
# And
my $aref = ['This', 'That', 'And', 'The', 'Other'];
print aref->[2];
# And

# having to quote like that really sucks, and that's why we got syntactic sugar
my @wakey_wakey = qw(coffee sugar cream);
push @wakey_wakey, 'spoon';
# add spoon to right-hand side
my $cutlery = pop @wakey_wakey;
# remove spoon
unshift @wakey_wakey, 'cup';
# add cup to left-hand side
my $container = shift @wakey_wakey;
# remove cup

my @multi_dimensional = (
[0, 1, 2, 3],
[qw(a b c d e f g)],
[qw(! $ %

==[[Pop11]]==
[[Category:Pop11]]

Pop11 distinguishes between vectors and arrays. Vectors are one
dimensional and the lowest index is 1. There is special shorthand
syntax to create vectors:

;;; General creation of vectors, create initialized vector.
lvars v1 = consvector(1, 'a', "b", 3);
;;; Shorthand notation
lvars v2 = {1 'a' b};
;;; Create vector filled with word undef (to signal that elements
;;; are uninitialized)
lvars v3 = initv(3)

Pop11 arrays may have arbitrary lower and upper bounds:

;;; Create array with first index ranging from 2 to 5 and second
;;; index from -1 to 1, initialized with 0
vars a1 = newarray([2 5 -1 1], 0);

==[[Python]]==
[[Category:Python]]

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

empty = []
numbers = [1, 2, 3, 4, 5]
zeros = [0] * 10
anything = [1, 'foo', 2.57, None, zeros]
digits = range(10) # 0, 1 ... 9
evens = range(0,10,2) # 0, 2, 4 ... 8
evens = [x for x in range(10) if not x % 2] # same using list comprehension
words = 'perl style'.split()

Tuples are immutable arrays. Note hat tuples are defined by the "," - the parenthesis are optional:

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:

<pre>
>>> list('abc')
['a', 'b', 'c']
>>> tuple('abc')
('a', 'b', 'c')
>>> list({'a': 1, 'b': 2, 'c': 3})
['a', 'c', 'b']
>>> open('file', 'w').write('1\n2\n3\n')
>>> list(open('file'))
['1\n', '2\n', '3\n']
</pre>

==[[Ruby]]==
[[Category:Ruby]]
I've used the same examples as the Python-example above.
.
empty = []
#or:
empty = Array.new
numbers = [1, 2, 3, 4, 5]
zeros = [0] * 10
anything = [1, 'foo', 2.57, zeros]

==[[Toka]]==
[[Category:Toka]]
Toka allows creation of an array using is-array. Access to the elements is done using
get-element, put-element, get-char-element, and put-char-element functions. You can
not initialize the values automatically using the core array functions.

100 cells is-array foo
100 chars is-array bar

Latest revision as of 15:07, 29 November 2019

Please do not add new code, and merge existing code to the Arrays task.

Creating an Array was a programming task. It has been deprecated for reasons that are discussed in its talk page.

This task is about numerically-indexed arrays. For hashes or associative arrays, please see Creating an Associative Array.

In this task, the goal is to create an array. Mention if the array base begins at a number other than zero. In addition, demonstrate how to initialize an array variable with data.

Retrieved from "https://rosettacode.org/wiki/Creating_an_Array?oldid=6178"