This article relies largely or entirely on a single source. (June 2013) |
This comparison of programming languages (array) compares the features of array data structures or matrix processing for various computer programming languages.
Syntax
editArray dimensions
editThe following list contains syntax examples of how to determine the dimensions (index of the first element, the last element or the size in elements).
Some languages index from zero. Some index from one. Some carry no such restriction, or even allow indexing by any enumerated type, not only integers.
Languages | Size | First | Last |
---|---|---|---|
Ada | name'Length | name'First | name'Last |
ALGOL 68 | UPB name - LWB name+1 2 UPB name - 2 LWB name+1 etc. |
LWB name 2 LWB name etc. |
UPB name 2 UPB name |
APL | ⍴ name (⍴ name)[index] |
⎕IO | (⍴ name)-~⎕IO (⍴ name)[index]-~⎕IO |
AWK | length | 1 | asorti |
C#, Visual Basic (.NET), Windows PowerShell, F# | name.Length | name.GetLowerBound(dimension) | name.GetUpperBound(dimension) |
CFML | arrayLen(name) name.len() |
1 | name.len() |
Ch | max(shape(name)) | 0 | max(shape(name))-1 |
Common Lisp | (length name) | 0 | (1- (length name)) |
D | name.length | 0 | name.length-1 $-1 |
Fortran | size(name) | lbound(name) | ubound(name) |
Go | len(name) | 0 | len(name) - 1 |
Haskell | rangeSize (bounds name) | fst (bounds name) | snd (bounds name) |
ISLISP | (length name) | 0 | (1- (length name)) |
Icon | *name | 1 | *name |
Cobra, D, Haxe, Java, JavaScript, Scala | name.length | 0 | name.length - 1 |
J | #name | 0 | <:@#name |
JavaScript (ES2022) | name.length | 0 name.at(0)[1] |
name.length - 1 name.at(-1)[1] |
Julia | length(name) size(name) |
begin first.(axes(name)) |
end last.(axes(name)) |
Lingo | count(name) | 1 | getLast(name) |
LiveCode | length(name) | 1 first |
-1 last |
Lua | #name | 1 by convention; any integer[2] | #name |
Mathematica | Length[name] | 1 First[name] |
-1 Last[name] |
MATLAB, GNU Octave | length(name) | 1 | end |
Nim | name.len | name.low[3] | name.high |
Oberon | LEN(name) | 0 | LEN(name) - 1 |
Object Pascal | Length(name) | 0 low(name) |
Length(name)-1 high(name) |
Objective-C (NSArray * only)
|
[name count] | 0 | [name count] - 1 |
OCaml | Array.length name | 0 | Array.length name - 1 |
Perl | scalar(@name) | $[ | $#name |
PHP | count(name) | 0 | count(name) - 1 |
PL/I | dim(name[,dim]) | lbound(name[,dim]) | hbound(name[,dim]) |
Python | len(name) | 0 | -1 len(name) - 1 |
R | length(name) | 1 | length(name) |
Raku | @name.elems | 0 | @name.end |
Red | length? name | name/1 first name |
last name |
Ruby | name.size | 0 name.first |
-1 name.size - 1 name.last |
Rust | name.len() | 0 | name.len() - 1 |
S-Lang | length(name) | 0 | -1 length(name)-1 |
Scheme | (vector-length vector) | 0 | (- (vector-length vector) 1) |
Smalltalk | name size | 1 name first |
name size name last |
Swift | name.count | 0 | name.count - 1 |
Unicon | *name | 1 | *name |
Visual Basic | UBound(name)-LBound(name)+1 | LBound(name) | UBound(name) |
Wolfram Language | Length[name] | 1 First[name] |
-1 Last[name] |
Xojo | UBound(name) | 0 | UBound(name) |
XPath/XQuery | count($name) | 1 | count($name) last() array:size(name)[4] |
Indexing
editThe following list contains syntax examples of how to access a single element of an array.
Format | Languages |
---|---|
name[index] or name[index1, index2] etc. | ALGOL 58, ALGOL 60, ALGOL 68, AWK, Julia, Modula, Pascal, Object Pascal, C#, S-Lang[5] Icon, Unicon |
name[index] or name[index1; index2] etc. or index⌷name or index1 index2⌷name etc. |
APL |
name[index] | ActionScript, C, CFML, Ch, Cobra, C++, D, Go, Haxe, Java, JavaScript, Lingo, Lua, Nim, Objective-C (NSArray * ), Perl,[5] PHP, Python,[5] R, Ruby,[5] Rust, Swift
|
$name[index] | Perl,[5] Windows PowerShell,[5] XPath/XQuery[4] |
@name[index] | Raku |
name(index) or name(index1, index2) etc. | Ada, ALGOL W, BASIC, COBOL, Fortran, RPG, GNU Octave, MATLAB, PL/I, Scala, Visual Basic, Visual Basic (.NET), Xojo |
$name(index) | XPath/XQuery[4] |
name.(index) | OCaml |
name.[index] | F#, OCaml |
name/index | Red |
name ! index | Haskell |
$name ? index | XPath/XQuery[4] |
(vector-ref name index) | Scheme |
(aref name index) | Common Lisp |
(elt name index) | ISLISP |
name[[index]] | Mathematica,[5] Wolfram Language |
name at:index | Smalltalk |
[name objectAtIndex:index] | Objective-C (NSArray * only)
|
index{name | J |
name.item(index) or name @ index[6] | Eiffel |
Slicing
editThe following list contains syntax examples of how a range of element of an array can be accessed.
In the following table:
- first – the index of the first element in the slice
- last – the index of the last element in the slice
- end – one more than the index of last element in the slice
- len – the length of the slice (= end - first)
- step – the number of array elements in each (default 1)
Format | Languages |
---|---|
name[first:last] | ALGOL 68,[7] Julia, Icon, Unicon |
name[first+(⍳len)-⎕IO] | APL |
name[first:end:step] | Python[8][9] |
name[first:end] | Go |
name[first..last] | Pascal, Object Pascal, Delphi, Nim |
$name[first..last] | Windows PowerShell |
@name[first..last] | Perl[10] |
name[first..last] name[first...end] name[first, len] |
Ruby[9] |
copy/part skip name first len | Red |
name(first..last) | Ada[7] |
name(first:last) | Fortran,[7][8] GNU Octave, MATLAB[7][10] |
name[[first;;last;;step]] | Mathematica,[7][8][9] Wolfram Language |
name[[first:last]] | S-Lang[7][8][10] |
name.[first..step..last] | F# |
name.slice(first, end) | Haxe, JavaScript, Scala |
name.slice(first, len) | CFML |
array_slice(name, first, len) | PHP[9] |
(subseq name first end) | Common Lisp |
(subseq name first end) | ISLISP |
Array.sub name first len | OCaml |
[name subarrayWithRange:NSMakeRange(first, len)] | Objective-C (NSArray * only)
|
(first([+i.@(-~)end){name | J |
name[first..<end] name[first...last] |
Swift |
name copyFrom: first to:last name copyFrom: first count:len |
Smalltalk |
name[first..end] | D, C#[11][12] |
name[first..end] name[first..=last] |
Rust |
name[first:end] | Cobra |
table.move(name, first, last, 1, {})
|
Lua[13] |
Array system cross-reference list
editLanguage | Default base index |
Specifiable index type[14] |
Specifiable base index |
Bound check | Multidimensional | Dynamically-sized | Vectorized operations |
---|---|---|---|---|---|---|---|
Ada | index type[15] | yes | yes | checked | yes | init[16] | some, others definable[17] |
ALGOL 68 | 1 | no[18] | yes | varies | yes | yes | user definable |
APL | 1 | ? | 0 or 1[19] | checked | yes | yes | yes |
AWK | 1 | yes, implicitly | no | unchecked | yes, as delimited string | yes, rehashed | no |
BASIC | 0 | ? | no | checked | no | init[16] | ? |
C | 0 | no | no[20] | unchecked | partially | init,[16][21] heap[22] | no |
Ch | 0 | no | no | checked | yes, also array of array[23] | init,[16][21] heap[22] | yes |
C++[17] | 0 | no | no[20] | unchecked | yes, also array of array[23] | heap[22] | no |
C# | 0 | no | partial[24] | checked | yes | heap[22][25] | yes (LINQ select) |
CFML | 1 | no | no | checked | yes, also array of array[23] | yes | no |
COBOL | 1 | no[26] | no | checked | array of array[23][27] | no[28] | some intrinsics |
Cobra | 0 | no | no | checked | array of array[23] | heap | ? |
Common Lisp | 0 | ? | no | checked[29] | yes | yes | yes (map or map-into) |
D | 0 | yes[30] | no | varies[31] | yes | yes | ? |
F# | 0 | no | partial[24] | checked | yes | heap[22][25] | yes (map) |
FreeBASIC | 0 | no | yes | checked | yes | init,[16] init[32] | ? |
Fortran | 1 | yes | yes | varies[33] | yes | yes | yes |
FoxPro | 1 | ? | no | checked | yes | yes | ? |
Go | 0 | no | no | checked | array of array[23] | no[34] | no |
Hack | 0 | yes | yes | checked | yes | yes | yes |
Haskell | 0 | yes[35] | yes | checked | yes, also array of array[23] | init[16] | ? |
IDL | 0 | ? | no | checked | yes | yes | yes |
ISLISP | 0 | ? | no | checked | yes | init[16] | yes (map or map-into) |
J | 0 | ? | no | checked | yes | yes | yes |
Java[17] | 0 | no | no | checked | array of array[23] | init[16] | ? |
JavaScript | 0 | no | no | checked[36] | array of array[23] | yes | yes |
Julia | 1 | yes | yes | checked (can be skipped locally; or globally by user) | yes, also array of array | yes | yes |
Lingo | 1 | ? | ? | unchecked | yes | yes | yes |
Lua | 1 | ? | partial[37] | checked | array of array[23] | yes | ? |
Mathematica | 1 | no | no | checked | yes | yes | yes |
MATLAB | 1 | ? | no | checked | yes[38] | yes | yes |
Nim | 0 | yes[3] | yes | optional[39] | array of array[23] | yes | yes[40] |
Oberon | 0 | ? | no | checked | yes | no | ? |
Oberon-2 | 0 | ? | no | checked | yes | yes | ? |
Objective-C[17] | 0 | no | no | checked | array of array[23] | yes | no |
OCaml | 0 | no | no | checked by default | array of array[23] | init[16] | ? |
Pascal, Object Pascal | index type[15] | yes | yes | varies[41] | yes | varies[42] | some |
Perl | 0 | no | yes ($[ )
|
checked[36] | array of array[23] | yes | no[43] |
Raku | 0 | no | no | checked[36] | yes | yes | yes |
PHP | 0 | yes[44] | yes[44] | checked[44] | yes | yes | yes |
PL/I | 1 | yes | yes | optional | yes | no | yes[45] |
Python | 0 | no | no | checked | array of array[23] | yes | no[46] |
RPG | 1 | no | no | ? | no | no | ? |
R | 1 | ? | no | unchecked | yes, also array of array | yes | yes |
Ring | 1 | ? | partial[37] | checked | array of array[23] | yes | ? |
Ruby | 0 | no | no | checked[36] | array of array[23] | yes | ? |
Rust | 0 | no | no | checked | array of array[23] | no | ? |
Sass | 1 | no | no | checked | array of array[23] | init[31] | ? |
S-Lang | 0 | ? | no | checked | yes | yes | yes |
Scala | 0 | no | no | checked | array of array[23] | init[16] | yes (map) |
Scheme | 0 | ? | no | checked | array of array[23] | init[16] | yes (map) |
Smalltalk[17] | 1 | ? | no | checked | array of array[23] | yes[47] | ? |
Swift | 0 | no | no | checked | array of array[23] | yes | ? |
Visual Basic (classic) | 0, 1, or index type[48] | no | yes | checked | yes | yes | ? |
Visual Basic (.NET) | 0 or index type[48] | no | partial[24] | checked | yes | yes | yes (LINQ select) |
Wolfram Language | 1 | no | no | checked | yes | yes | yes |
Windows PowerShell | 0 | no | no | checked | yes | heap | ? |
Xojo | 0 | no | no | checked | yes | yes | no |
XPath/XQuery | 1 | no | no | checked | array of array[4][23] | yes | yes |
Vectorized array operations
editSome compiled languages such as Ada and Fortran, and some scripting languages such as IDL, MATLAB, and S-Lang, have native support for vectorized operations on arrays. For example, to perform an element by element sum of two arrays, a and b to produce a third c, it is only necessary to write
c = a + b
In addition to support for vectorized arithmetic and relational operations, these languages also vectorize common mathematical functions such as sine. For example, if x is an array, then
y = sin (x)
will result in an array y whose elements are sine of the corresponding elements of the array x.
Vectorized index operations are also supported. As an example,
even = x(2::2);
odd = x(::2);
is how one would use Fortran to create arrays from the even and odd entries of an array. Another common use of vectorized indices is a filtering operation. Consider a clipping operation of a sine wave where amplitudes larger than 0.5 are to be set to 0.5. Using S-Lang, this can be done by
y = sin(x); y[where(abs(y)>0.5)] = 0.5;
Mathematical matrix operations
editLanguage/ Library |
Create | Determinant | Transpose | Element | Column | Row | Eigenvalues |
---|---|---|---|---|---|---|---|
APL | m←dims⍴x11 x12 ...
|
-.×m
|
⍉m
|
m[i;j] or i j⌷m
|
m[;j] or j⌷[2]m orj⌷⍤1⊢m or j⌷⍉m
|
m[i;] or i⌷m
|
⌹⍠1⊢m
|
Fortran | m = RESHAPE([x11, x12, ...], SHAPE(m))
|
TRANSPOSE(m)
|
m(i,j)
|
m(:,j)
|
m(i,:)
|
||
Ch[49] | m = {... }
|
determinant(m)
|
transpose(m)
|
m[i-1][j-1]
|
shape(m,0)
|
shape(m,1)
|
eigen(output, m, NULL)
|
Julia and its standard libraryLinearAlgebra
|
m = [1 2; 3 4] or
m = [
1 2
3 4
]
|
det(m)
|
transpose(m) or
|
m[i, j]
|
m[:, j]
|
m[i, :]
|
eigen(m).values
|
Mathematica / Wolfram Language |
{{x11, x12, ...}, ...}
|
Det[m]
|
Transpose[m]
|
m[[i,j]]
|
m[[;;,j]]
|
m[[i]]
|
Eigenvalues[m]
|
MATLAB / GNU Octave |
m = [...]
|
det(m)
|
m.'
|
m(i,j)
|
m(:,j)
|
m(i,:)
|
eig(m)
|
NumPy | m = mat(...)
|
linalg.det(m)
|
m.T
|
m[i-1,j-1]
|
m[:,j-1]
|
m[i-1,:]
|
linalg.eigvals(m)
|
R | m <- matrix(...) or m <- array(...)
|
det(m)
|
t(m)
|
m[i, j]
|
m[, j]
|
m[i, ]
|
eigen(m)
|
S-Lang | m = reshape([x11, x12, ...], [new-dims])
|
m = transpose(m)
|
m[i,j]
|
m[*,j]
|
m[j,*]
|
||
SymPy | m = Matrix(...)
|
m.det()
|
m.T
|
m[i-1,j-1]
|
m.col(j-1)
|
m.row(i-1)
|
m.eigenvals()
|
References
edit- ^ a b "ECMAScript® 2025 Language Specification".
- ^ "Programming in Lua : 11.1".
- ^ a b "Nim Tutorial (Part I)".
- ^ a b c d e XPath/XQuery has two kinds of arrays. Sequences (1,2,3) which cannot nest and in the XPath/XQuery 3.1 version arrays array { 1,2,3} or [1,2,3] which can.
- ^ a b c d e f g The index may be a negative number, indicating the corresponding number of places before the end of the array.
- ^ "Eiffeldoc : ARRAY".
- ^ a b c d e f Slices for multidimensional arrays are also supported and defined similarly.
- ^ a b c d Slices of the type
first:last:step
are also supported. - ^ a b c d last or end may be a negative number, indicating to stop at the corresponding number of places before the end of the array.
- ^ a b c More generally, for 1-d arrays Perl and S-Lang allow slices of the form
array[indices]
, whereindices
can be a range such mentioned in footnote 2 or an explicit list of indices, e.g., '[0,9,3,4]
', or a mix of both, e.g.,A[[[0:3]],7,9,[11:2:-3]]]
. - ^ C# 8.0 proposed feature (as of 29 August 2019[update])
- ^ "Ranges - C# 8.0 language proposals". Microsoft Docs. Microsoft. Retrieved 29 August 2019.
- ^ "Lua 5.3 Reference Manual". www.lua.org. Retrieved 2022-04-02.
- ^ The index type can be a freely chosen integer type, enumerated type, or character type. For arrays with non-compact index types see: Associative array
- ^ a b The default base index is the lowest value of the index type used
- ^ a b c d e f g h i j k Size can only be chosen on initialization after which it is fixed.
- ^ a b c d e This list is strictly comparing language features. In every language (even assembly language) it is possible to provide improved array handling via add on libraries. This language has improved array handling as part of its standard library
- ^ ALGOL 68 arrays must be subscripted (and sliced) by type INT. However a hash function could be used to convert other types to INT. e.g. name[hash("string")]
- ^ The indexing base can be 0 or 1 as per the System Variable ⎕IO. This value may apply to the whole "workspace", or be localized to a user-defined function or a single primitive function by use of the Variant operator (⍠).
- ^ a b Because C does not bound-check indices, a pointer to the interior of any array can be defined that will symbolically act as a pseudo-array that accommodates negative indices or any integer index origin.
- ^ a b C99 allows for variable size arrays; however there is almost no compiler available to support this new feature
- ^ a b c d e Size can only be chosen on initialization when memory is allocated on the heap, as distinguished from when it is allocated on the stack. This note need not be made for a language that always allocates arrays on the heap.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x Allows arrays of arrays which can be used to emulate most—but not all—aspects multi-dimensional arrays
- ^ a b c The base can be changed when initializing with System.Array.CreateInstance (which returns System.Array), but not when using the language syntax. Arrays with non-zero base indices are not the same type as those with zero base indices and cannot be manipulated using language syntax (the GetValue and SetValue methods must be used instead) or downcast to a specific type (T[] in C#, or T() in VB.NET), preventing breakage of code assuming base indices of zero.
- ^ a b Allows creating fixed-size arrays in "unsafe" code, allowing enhanced interoperability with other language
- ^ COBOL arrays may be indexed with "INDEX" types, distinct from integer types
- ^ While COBOL only has arrays-of-arrays, array elements can be accessed with a multi-dimensional-array-like syntax, where the language automatically matches the indexes to the arrays enclosing the item being referenced
- ^ COBOL provides a way to specify that the usable size of an array is variable, but this can never be greater than the declared maximum size, which is also the allocated size
- ^ Most Common Lisp implementations allow checking to be selectively disabled
- ^ Associative Arrays - D Programming Language
- ^ a b Behaviour can be tuned via compiler switches. As in DMD 1.0 bounds are checked in debug mode and unchecked in release mode for efficiency
- ^ FreeBASIC supports both variable array lengths and fixed length arrays. Arrays declared with no index range are created as variable-length arrays, while arrays with a declared range are created as fixed-length arrays
- ^ Almost all Fortran implementations offer bounds checking options via compiler switches. However by default, bounds checking is usually turned off for efficiency
- ^ While Golang's Array type is not dynamically sized, the data type Slice is dynamically-sized and is much more common in use than arrays.
- ^ Haskell arrays (Data.Array) allow using any type which is an instance of Ix as index type. So a custom type can be defined and used as an index type as long as it instances Ix. Also, tuples of Ix types are also Ix types; this is commonly used to implement multi-dimensional arrays
- ^ a b c d In these languages, one can access or write to an array index greater than or equal to the length of the array, and the array will implicitly grow to that size. This may appear at first as if the bounds are not checked; however, the bounds are checked to decide to grow the array, and you do not have unsafe memory access like you do in C.
- ^ a b By specifying a base index, arrays at an arbitrary base can be created. However, by default, Lua's length operator does not consider the base index of the array when calculating the length. This behavior can be changed via metamethods.
- ^ At least 2 dimensions (scalar numbers are 1×1 arrays, vectors are 1×n or n×1 arrays).
- ^ "Nim Compiler User Guide".
- ^ "Vectorization - R-style logical vector operation in Nim".
- ^ Many implementations (Turbo Pascal, Object Pascal (Delphi), Free Pascal) allow the behaviour to be changed by compiler switches and in-line directives
- ^ Varies by implementation. Newer implementations (Free Pascal, Object Pascal (Delphi)) allow heap-based dynamic arrays.
- ^ Standard Perl array data types do not support vectorized operations as defined here. However, the Perl Data Language extension adds array objects with this ability.
- ^ a b c PHP's "arrays" are associative arrays. You can use integers and strings as the keys (indexes); floats can also be used as the key but are truncated to integers. There is not really any "base index" or "bounds"
- ^ Size can be chosen when the array is declared, or when it is allocated, after which it is fixed.
- ^ The standard Python array type,
list
, does not support vectorized operations as defined here. However, the numpy extension adds array objects with this ability - ^ The class Array is fixed-size, but OrderedCollection is dynamic
- ^ a b Microsoft QBASIC, QuickBASIC, Visual Basic, and VBA all had/have the ability to specify Option Base 1, which caused all arrays in the module to default starting at 1 instead of 0. Support for Option Base was phased out in Visual Basic (.NET). In various Microsoft BASIC implementations, arrays can be DIMensioned using to to specify the minimum and maximum index values (e.g. DIM MyArray(2 to 50) AS STRING would have the first index at 2 instead of the default).
- ^ Ch numerical features