Comparison of programming languages (array)

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This comparison of programming languages (array) compares the features of array data structures or matrix processing for over 48 various computer programming languages.

Syntax[edit]

Array dimensions[edit]

The following list contains syntax examples on how to determine the dimensions (index of the first element, the last element and/or the size in elements):

Size First Last Languages
name'Length name'First name'Last Ada
UPB name - LWB name+1 or
2 UPB name - 2 LWB name+1 etc.
LWB name or 2 LWB name etc. UPB name or 2 UPB name etc. ALGOL 68
name.Length name.GetLowerBound(dimension) name.GetUpperBound(dimension) C#, Visual Basic .NET, Windows PowerShell, F#
max(shape(name)) 0 max(shape(name))-1 Ch
(length name) 0 (1- (length name)) Common Lisp
SIZE(name) LBOUND(name) UBOUND(name) Fortran
len(name) 0 len(name) - 1 Go
rangeSize (bounds name) fst (bounds name) snd (bounds name) Haskell
(length name) 0 (1- (length name)) ISLISP
name.length 0 name.length - 1 Java, JavaScript, D, Scala
#name 0 <:@#name J
#name 1 #name Lua
Length[name] 1 or First[name] -1 or Last[name] Mathematica
length(name) 1 end MATLAB, GNU Octave, Julia
Length(name) name[0] name[Length(name)-1] Object Pascal
[name count] 0 [name count] - 1 Objective-C (NSArray * only)
Array.length name 0 Array.length name - 1 OCaml
scalar(@name) $[ $#name Perl
@name.elems 0 @name.end Perl 6
count($name) 0 count($name) - 1 PHP
len(name) 0 -1 or len(name) - 1 Python
name.size 0 (name.first will also refer to this element) -1 or name.size - 1 (name.last will also refer to this element) Ruby
length(name) 0 -1 or length(name)-1 S-Lang
(vector-length vector) 0 (- (vector-length vector) 1) Scheme
name size 1 (name first will also refer to this element) name size (name last will also refer to this element) Smalltalk
UBound(name)-LBound(name)+1 LBound(name) UBound(name) Visual Basic

Indexing[edit]

The following list contains Syntax examples on how a single element of an array can be accessed.

Format Languages
name[index] or name[index1, index2] etc. ALGOL 68, Pascal, Object Pascal, C#, S-Lang[1]
name[index] C, Ch, C++, D, Go, Java, ActionScript 3.0, JavaScript, Julia, Lua, Perl,[1] Python,[1] Ruby[1]
$name[index] Perl,[1] PHP, Windows PowerShell[1]
@name[index] Perl 6
name(index) Ada, BASIC, COBOL, Fortran, RPG, MATLAB, Scala, Visual Basic, Visual Basic .NET,
name.(index) OCaml
name.[index] F#
name ! index Haskell
(vector-ref name index) Scheme
(aref name index) Common Lisp
(elt name index) ISLISP
name [[index]] Mathematica[1]
name at:index Smalltalk
[name objectAtIndex:index] Objective-C (NSArray * only)
index{name J

Slicing[edit]

The following list contains syntax examples on 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,[2] Julia
name[first:end:step] Python,[3][4] Go
name[first..last] Pascal, Object Pascal, Delphi, D
$name[first..last] Windows PowerShell
@name[first..last] Perl[5]
name[first..last]
name[first...end]
name[first, len]
Ruby[4]
name(first..last) Ada[2]
name(first:last) Fortran,[2][3] MATLAB[2][5]
name[[first;;last]] Mathematica[2][3][4]
name[[first:last]] S-Lang[2][3][5]
name.[first..last] F#
name.slice(first, last) JavaScript, Scala
array_slice(name, first, len) PHP[4]
(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

Array system cross-reference list[edit]

Programming language Default base index Specifiable index type[6] Specifiable base index Bound check Multidimensional Dynamically-sized Vectorized operations
Ada index type[7] yes yes checked yes init[8] some, others definable[9]
ALGOL 68 1 no[10] yes varies yes yes user definable
APL  ?  ? 0 or 1[11] checked yes init[8] yes
BASIC 0  ? no checked no init[8]  ?
C 0 no no[12] unchecked yes, also array of array[13] init,[8][14] heap[15] no
Ch 0 no no checked yes, also array of array[13] init,[8][14] heap[15] yes
C++[9] 0 no no[12] unchecked yes, also array of array[13] heap[15] no
C# 0 no no checked yes heap[15][16] yes (LINQ select)
COBOL 1 no[17] no checked array of array[13][18] no[19] some intrinsics
Common Lisp 0  ? no checked[20] yes yes yes (map or map-into)
D 0 yes[21] no varies[22] yes yes  ?
F# 0 no no checked yes heap[15][16] yes (map)
FreeBASIC 0 no yes checked yes init,[8] init[23]  ?
Fortran 1 yes yes varies[24] yes yes yes
FoxPro 1  ? no checked yes yes  ?
Go 0 no no checked array of array[13] no no
Haskell none (specified on init) yes[25] yes checked yes, also array of array[13] init[8]  ?
IDL 0  ? no checked yes yes yes
ISLISP 0  ? no checked yes init[8] yes (map or map-into)
J 0  ? no checked yes init[8] yes
Java[9] 0 no no checked array of array[13] init[8]  ?
JavaScript 0 no no checked[26] array of array[13] yes yes
Julia 1 yes no checked yes yes yes
Lua 1  ? partial[27] checked array of array[13] yes  ?
Mathematica 1 no no checked yes yes yes
MATLAB 1  ? no checked yes[28] yes yes
Oberon 0  ? no checked yes no  ?
Oberon-2 0  ? no checked yes yes  ?
Objective-C[9] 0 no no checked array of array[13] yes no
OCaml 0 no no checked by default array of array[13] init[8]  ?
Pascal, Object Pascal index type[7] yes yes varies[29] yes varies[30] some
Perl 0 no yes ($[) checked[26] array of array[13] yes no[31]
Perl 6 0 no no checked[26] yes yes yes
PHP 0 yes[32] yes[32] checked[32] yes yes yes
PL/I 1  ? yes checked yes no  ?
Python 0 no no checked array of array[13] yes no[33]
RPG 1 no no  ? no no  ?
Ruby 0 no no checked[26] array of array[13] yes  ?
S-Lang 0  ? no checked yes yes yes
Scala 0 no no checked array of array[13] init[8] yes (map)
Scheme 0  ? no checked array of array[13] init[8] yes (map)
Smalltalk[9] 1  ? no checked array of array[13] yes[34]  ?
Visual Basic 0 no yes checked yes yes  ?
Visual Basic .NET 0 no no checked yes yes yes (LINQ select)
Windows PowerShell 0 no no checked yes heap  ?
XPath 1 no no checked no yes yes
Programming language Default base index Specifiable index type[6] Specifiable base index Bound check Multidimensional Dynamically-sized Vectorized operations

Vectorized array operations[edit]

Some 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 may accomplished by

    y = sin(x);
    y[where(abs(y)>0.5)] = 0.5;

Mathematical matrices management[edit]

Language/
Library
Create Determinant Transpose Element Column Row Eigenvalues
Fortran m = RESHAPE([x11, x12, ...], SHAPE(m)) TRANSPOSE(m) m(i,j) m(:,j) m(i,:)
Ch [35] m = {...} determinant(m) transpose(m) m[i-1][j-1] shape(m,0) shape(m,1) eigen(output, m, NULL)
Mathematica m = {{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(...) m.T m[i-1,j-1] m[:,i-1] m[i-1,:]
S-Lang m = reshape([x11, x12, ...], [new-dims]) m = transpose(m) m[i,j] m[*,j] m[j,*]
SymPy m = Matrix(...) m.T m[i-1,j-1]

References[edit]

  1. ^ 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.
  2. ^ a b c d e f Slices for multidimensional arrays are also supported and defined similarly.
  3. ^ a b c d Slices of the type first:last:step are also supported.
  4. ^ 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.
  5. ^ a b c More generally, for 1-d arrays Perl and S-Lang permit slices of the formarray[indices], where indices can be a range such mentioned in footnote 2 or an explicit list of indices, e.g., '[0,9,3,4]', as well as a combination of the two, e.g., A[[[0:3]],7,9,[11:2:-3]]].
  6. ^ a b 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
  7. ^ a b The default base index is the lowest value of the index type used
  8. ^ a b c d e f g h i j k l m Size can only be chosen on initialization after which it is fixed
  9. ^ a b c d e This list is strictly comparing language features. In every language (even assembler) it is possible to provide improved array handling via add on libraries. This language has improved array handling as part of its standard library
  10. ^ 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")]
  11. ^ The indexing base can be 0 or 1, but is set for a whole "workspace"
  12. ^ 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
  13. ^ a b c d e f g h i j k l m n o p q Allows arrays of arrays which can be used to emulate most—but not all—aspects multi-dimensional arrays
  14. ^ a b C99 allows for variable size arrays; however there is almost no compiler available to support this new feature
  15. ^ 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
  16. ^ a b Allows creation of fixed-size arrays in "unsafe" code, allowing for enhanced interoperability with other language
  17. ^ COBOL arrays may be indexed with "INDEX" types, distinct from integer types
  18. ^ 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
  19. ^ 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
  20. ^ Most Common Lisp implementations allow checking to be selectively disabled
  21. ^ Associative Arrays - D Programming Language
  22. ^ Behaviour can be tuned using compiler switches. As in DMD 1.0 bounds are checked in debug mode and unchecked in release mode for efficiency reasons
  23. ^ 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
  24. ^ Almost all Fortran implementations offer bounds checking options via compiler switches. However by default, bounds checking is usually turned off for efficiency reasons
  25. ^ 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
  26. ^ 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 in order to decide to grow the array, and you do not have unsafe memory access like you do in C
  27. ^ 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
  28. ^ At least 2 dimensions (scalar numbers are 1×1 arrays, vectors are 1×n or n×1 arrays)
  29. ^ Many implementations (Turbo Pascal, Object Pascal (Delphi), FreePascal) allow the behaviour to be changed by compiler switches and in-line directives
  30. ^ Varies by implementation. Newer implementations (FreePascal, Object Pascal (Delphi)) permit heap-based dynamic arrays
  31. ^ Standard Perl array data types do not support vectorized operations as defined here. However, the Perl Data Languageextension adds array objects with this ability
  32. ^ 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"
  33. ^ The standard Python array type, list, does not support vectorized operations as defined here. However, the numpy extension adds array objects with this ability
  34. ^ The class Array is fixed-size, but OrderedCollection is dynamic
  35. ^ Ch numerical features