Array length: Difference between revisions
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PrintLn(a.Length); |
PrintLn(a.Length); |
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</lang> |
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=={{header|Easyprog.online}}== |
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<lang>fruit$[] = [ "apples" "oranges" ] |
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print len fruit$[]</lang> |
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=={{header|EchoLisp}}== |
=={{header|EchoLisp}}== |
Revision as of 13:25, 21 May 2019
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
- Related task
11l
<lang 11l>print([‘apple’, ‘orange’].len)</lang>
- Output:
2
360 Assembly
Array length is computed at compilation time with the formula : (AEND-A)/L'A <lang 360asm>* Array length 22/02/2017 ARRAYLEN START
USING ARRAYLEN,12 LR 12,15 end of prolog LA 1,(AEND-A)/L'A hbound(a) XDECO 1,PG+13 edit XPRNT PG,L'PG print BR 14 exit
A DC CL6'apple',CL6'orange' array AEND DC 0C PG DC CL25'Array length=' buffer
END ARRAYLEN</lang>
- Output:
Array length= 2
8th
<lang forth> ["apples", "oranges"] a:len . cr </lang>
- Output:
2
ABAP
The concept of arrays does not exist in ABAP, instead internal tables are used. Since ABAP Version 7.40 they can be accessed with the common index notation. Note that the index starts at 1 and out of bound access raises an exception. The built-in function "lines" returns the number of records.
<lang ABAP> report z_array_length.
data(internal_table) = value stringtab( ( `apple` ) ( `orange` ) ).
write: internal_table[ 1 ] , internal_table[ 2 ] , lines( internal_table ). </lang>
- Output:
apple orange 2
Ada
<lang Ada>with Ada.Text_IO; use Ada.Text_IO;
procedure Array_Length is
Fruits : constant array (Positive range <>) of access constant String := (new String'("orange"), new String'("apple"));
begin
for Fruit of Fruits loop Ada.Text_IO.Put (Integer'Image (Fruit'Length)); end loop;
Ada.Text_IO.Put_Line (" Array Size : " & Integer'Image (Fruits'Length));
end Array_Length;</lang>
- Output:
6 5 Array Size: 2
ALGOL 68
<lang algol68># UPB returns the upper bound of an array, LWB the lower bound # []STRING fruits = ( "apple", "orange" ); print( ( ( UPB fruits - LWB fruits ) + 1, newline ) ) # prints 2 #</lang>
AntLang
<lang AntLang>array: seq["apple"; "orange"] length[array] /Works as a one liner: length[seq["apple"; "orange"]]</lang>
Apex
<lang apex>System.debug(new String[] { 'apple', 'banana' }.size()); // Prints 2</lang>
APL
<lang apl>⍴'apple' 'orange'</lang> Output:
2
AppleScript
<lang AppleScript> set theList to {"apple", "orange"} count theList -- or length of theList -- or number of items in theList </lang>
- Output:
2
No context or goal is provided for this task – sometimes for example, we may simply want to take the last member of an array, and counting the length to derive an index might well not be the best route.
More generally, we may learn more about AppleScript by defining length() ourselves. There are two basic functional approaches to doing that – we can write a simple recursive definition, or, if we have a higher order fold/reduce function (see Catamorphism) we can derive length() as:
fold (λx n -> 1 + n) 0
<lang AppleScript>on run
set xs to ["alpha", "beta", "gamma", "delta", "epsilon", ¬ "zeta", "eta", "theta", "iota", "kappa", "lambda", "mu"] {_length(xs), fold(xs, succ, 0), item 12 of xs, item -1 of xs} --> {12, 12, "mu", "mu"}
end run
-- TWO FUNCTIONAL DEFINITIONS OF LENGTH
-- 1. Recursive definition
on _length(xs)
if xs is [] then 0 else 1 + _length(rest of xs) end if
end _length
-- 2. fold (λx n -> 1 + n) 0
on succ(x)
1 + x
end succ
--[a] - > (a - > b) - > b - > [b] on fold(xs, f, startValue)
script mf property lambda : f end script set v to startValue repeat with x in xs set v to mf's lambda(v, x) end repeat
end fold </lang>
- Output:
{12, 12, "mu", "mu"}
ARM Assembly
<lang ARM Assembly> /* ARM assembly Raspberry PI */ /* program lenAreaString.s */
/* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ WRITE, 4 @ Linux syscall /* Initialized data */ .data szMessLenArea: .ascii "The length of area is : " sZoneconv: .fill 12,1,' ' szCarriageReturn: .asciz "\n"
/* areas strings */ szString1: .asciz "Apples" szString2: .asciz "Oranges" /* pointer items area */ tablesPoi: ptApples: .int szString1 ptOranges: .int szString2 ptVoid: .int 0
/* UnInitialized data */ .bss
/* code section */ .text .global main main: /* entry of program */
push {fp,lr} /* saves 2 registers */
ldr r1,iAdrtablesPoi @ begin pointer table mov r0,#0 @ counter
1: @ begin loop
ldr r2,[r1,r0,lsl #2] @ read string pointer address item r0 (4 bytes by pointer) cmp r2,#0 @ is null ? addne r0,#1 @ no increment counter bne 1b @ and loop ldr r1,iAdrsZoneconv @ conversion decimal bl conversion10S ldr r0,iAdrszMessLenArea bl affichageMess
2:
100: /* standard end of the program */
mov r0, #0 @ return code pop {fp,lr} @restaur 2 registers mov r7, #EXIT @ request to exit program swi 0 @ perform the system call
iAdrtablesPoi: .int tablesPoi iAdrszMessLenArea: .int szMessLenArea iAdrsZoneconv: .int sZoneconv iAdrszCarriageReturn: .int szCarriageReturn /******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess:
push {fp,lr} /* save registres */ push {r0,r1,r2,r7} /* save others registers */ mov r2,#0 /* counter length */
1: /* loop length calculation */
ldrb r1,[r0,r2] /* read octet start position + index */ cmp r1,#0 /* if 0 its over */ addne r2,r2,#1 /* else add 1 in the length */ bne 1b /* and loop */ /* so here r2 contains the length of the message */ mov r1,r0 /* address message in r1 */ mov r0,#STDOUT /* code to write to the standard output Linux */ mov r7, #WRITE /* code call system "write" */ swi #0 /* call systeme */ pop {r0,r1,r2,r7} /* restaur others registers */ pop {fp,lr} /* restaur des 2 registres */ bx lr /* return */
/***************************************************/ /* conversion register signed décimal */ /***************************************************/ /* r0 contient le registre */ /* r1 contient l adresse de la zone de conversion */ conversion10S:
push {r0-r5,lr} /* save des registres */ mov r2,r1 /* debut zone stockage */ mov r5,#'+' /* par defaut le signe est + */ cmp r0,#0 /* nombre négatif ? */ movlt r5,#'-' /* oui le signe est - */ mvnlt r0,r0 /* et inversion en valeur positive */ addlt r0,#1 mov r4,#10 /* longueur de la zone */
1: /* debut de boucle de conversion */
bl divisionpar10 /* division */ add r1,#48 /* ajout de 48 au reste pour conversion ascii */ strb r1,[r2,r4] /* stockage du byte en début de zone r5 + la position r4 */ sub r4,r4,#1 /* position précedente */ cmp r0,#0 bne 1b /* boucle si quotient different de zéro */ strb r5,[r2,r4] /* stockage du signe à la position courante */ subs r4,r4,#1 /* position précedente */ blt 100f /* si r4 < 0 fin */ /* sinon il faut completer le debut de la zone avec des blancs */ mov r3,#' ' /* caractere espace */
2:
strb r3,[r2,r4] /* stockage du byte */ subs r4,r4,#1 /* position précedente */ bge 2b /* boucle si r4 plus grand ou egal a zero */
100: /* fin standard de la fonction */
pop {r0-r5,lr} /*restaur desregistres */ bx lr
/***************************************************/ /* division par 10 signé */ /* Thanks to http://thinkingeek.com/arm-assembler-raspberry-pi/* /* and http://www.hackersdelight.org/ */ /***************************************************/ /* r0 contient le dividende */ /* r0 retourne le quotient */ /* r1 retourne le reste */ divisionpar10:
/* r0 contains the argument to be divided by 10 */ push {r2-r4} /* save registers */ mov r4,r0 ldr r3, .Ls_magic_number_10 /* r1 <- magic_number */ smull r1, r2, r3, r0 /* r1 <- Lower32Bits(r1*r0). r2 <- Upper32Bits(r1*r0) */ mov r2, r2, ASR #2 /* r2 <- r2 >> 2 */ mov r1, r0, LSR #31 /* r1 <- r0 >> 31 */ add r0, r2, r1 /* r0 <- r2 + r1 */ add r2,r0,r0, lsl #2 /* r2 <- r0 * 5 */ sub r1,r4,r2, lsl #1 /* r1 <- r4 - (r2 * 2) = r4 - (r0 * 10) */ pop {r2-r4} bx lr /* leave function */ bx lr /* leave function */
.Ls_magic_number_10: .word 0x66666667
</lang>
ATS
<lang ATS>
- include
"share/atspre_staload.hats"
- include
"share/atspre_staload_libats_ML.hats"
val A0 = array0_tuple<string> ( "apple", "orange" ) val () = println!("length(A0) = ", length(A0))
implement main0((*void*)) = ((*void*)) </lang>
AutoHotkey
<lang AutoHotkey>MsgBox % ["apple","orange"].MaxIndex()</lang>
- Output:
2
AutoIt
<lang AutoIt>Opt('MustDeclareVars',1) ; 1 = Variables must be pre-declared.
Local $aArray[2] = ["Apple", "Orange"] Local $Max = UBound($aArray) ConsoleWrite("Elements in array: " & $Max & @CRLF)
For $i = 0 To $Max - 1 ConsoleWrite("aArray[" & $i & "] = '" & $aArray[$i] & "'" & @CRLF) Next </lang>
- Output:
Elements in array: 2 aArray[0] = 'Apple' aArray[1] = 'Orange'
AWK
The main use of the length()-function is to determine the length of a string.
When used on an array, it returns the number of elements.
Another method to count the elements of the array is by using a variant of for().
<lang awk># usage: awk -f arraylen.awk
function countElements(array) {
for( e in array ) {c++} return c
}
BEGIN {
array[1] = "apple" array[2] = "orange"
print "Array length :", length(array), countElements(array) print "String length:", array[1], length(array[1])
}</lang>
- Output:
Array length : 2 2 String length: apple 5
BASIC
<lang basic>DIM X$(1 TO 2) X$(1) = "apple" X$(2) = "orange" PRINT UBOUND(X$) - LBOUND(X$) + 1</lang>
Commodore BASIC
<lang basic>10 DIM A$(2) 20 A$(1) = "ORANGE" 30 A$(2) = "APPLE" 40 PRINT LEN(A$(1))+LEN(A$(2))</lang>
Batch File
While batch files don't support arrays in the traditional sense, sets of variables forming somewhat of a pseudo-array are extremely useful. They are usually in the form of %name{number}%
. The below code gives an example of how to create an array from a list stored in a variable, and how to acquire the amount of entries in the array.
<lang dos> @echo off
- _main
setlocal enabledelayedexpansion
- This block of code is putting a list delimitered by spaces into an pseudo-array
- In practice, this could be its own function _createArray however for the demonstration, it is built in
set colour_list=red yellow blue orange green set array_entry=0 for %%i in (%colour_list%) do (
set /a array_entry+=1 set colours[!array_entry!]=%%i
)
call:_arrayLength colours echo _arrayLength returned %errorlevel% pause>nul exit /b
- _arrayLength returns the length of the array parsed to it in the errorcode
- _arrayLength
setlocal enabledelayedexpansion
- loop
set /a arrayentry=%arraylength%+1 if "!%1[%arrayentry%]!"=="" exit /b %arraylength% set /a arraylength+=1 goto loop </lang>
- Input:
red yellow blue orange green
- Output:
_arrayLength returned 5
Brat
<lang brat> p ["apple", "orange"].length </lang>
C
C features two kinds of arrays: static (compile-time, fixed size) and dynamic (allocated at runtime).
The length of a dynamic array cannot be acquired from the array itself - its length must be stored elsewhere.
For static arrays:
<lang c>
- include <stdio.h>
int main() {
const char *fruit[2] = { "apples", "oranges" };
// Acquire the length of the array by dividing the size of all elements (found // with sizeof(fruit)) by the size of the first element.
// Note that since the array elements are pointers to null-terminated character // arrays, the size of the first element is actually the size of the pointer // type - not the length of the string.
// This size, regardless of the type being pointed to, is 8 bytes, 4 bytes, or // 2 bytes on 64-bit, 32-bit, or 16-bit platforms respectively. int length = sizeof(fruit) / sizeof(fruit[0]);
printf("%d\n", length);
return 0;
} </lang>
A C pre-processor macro may be created for ease of use:
<lang c>
- define ARRAY_LENGTH(A) (sizeof(A) / sizeof(A[0]))
</lang>
Note that these arrays become pointers when passed as a parameter to a function. Thus, the length of an array parameter may not be required directly - a dedicated length parameter would be required.
C#
<lang csharp> using System;
class Program {
public static void Main() { var fruit = new[] { "apple", "orange" }; Console.WriteLine(fruit.Length); }
} </lang>
Note that any of the following array declarations could be used:
<lang csharp> var fruit = new[] { "apple", "orange" }; var fruit = new string[] { "apple", "orange" }; string[] fruit = new[] { "apple", "orange" }; string[] fruit = new string[] { "apple", "orange" }; string[] fruit = { "apple", "orange" }; </lang>
A shorter variant could also have been used:
<lang csharp> using static System.Console;
class Program {
public static void Main() { WriteLine(new[] { "apples", "oranges" }.Length); }
} </lang>
C++
C++ follows the same rules as C regarding static and dynamic arrays.
However, C++ has an additional std::array type (amongst other collections) in its standard library:
<lang cpp>
- include <array>
- include <iostream>
- include <string>
int main() {
std::array<std::string, 2> fruit { "apples", "oranges" }; std::cout << fruit.size(); return 0;
} </lang>
Note that char* or const char* could have been used instead of std::string.
In addition to the std::array type, the C++ standard library also provides dynamically-sized containers to hold arbitrary objects. These all support similar interfaces, though their implementations have different performance characteristics. <lang cpp>
std::vector<std::string> fruitV({ "apples", "oranges" }); std::list<std::string> fruitL({ "apples", "oranges" }); std::deque<std::string> fruitD({ "apples", "oranges" }); std::cout << fruitV.size() << fruitL.size() << fruitD.size() << std::endl;
</lang>
Of these, vector is probably the most widely used.
Ceylon
<lang ceylon>shared void run() { value array = ["apple", "orange"]; print(array.size); }</lang>
Clipper/XBase++
<lang Clipper/XBase++>/*
* nizchka: March - 2016 * This is a Clipper/XBase++ of RosettaCode Array_Length */
PROCEDURE MAIN()
LOCAL FRUIT := { "apples","oranges" }
? LEN(FRUIT)
RETURN </lang>
Outputs:
2
nizchka 23:27, 16 March 2016 (UTC)
Clojure
<lang clojure>; using count: (count ["apple" "orange"])
- OR alength if using Java arrays
(alength (into-array ["apple" "orange"]))</lang>
COBOL
Arrays in COBOL are usually referred to as tables. Tables can have fixed or variable (with known maximum) allocations, using a syntax of OCCURS DEPENDING ON. The value of the ODO identifier is the number of active elements in the table.
<lang COBOL> identification division.
program-id. array-length.
environment division. configuration section. repository. function all intrinsic.
data division. working-storage section. 01 table-one. 05 str-field pic x(7) occurs 0 to 5 depending on t1.
77 t1 pic 99.
procedure division. array-length-main. perform initialize-table perform display-table-info goback.
initialize-table. move 1 to t1 move "apples" to str-field(t1)
add 1 to t1 move "oranges" to str-field(t1).
*> add an extra element and then retract table size add 1 to t1 move "bananas" to str-field(t1). subtract 1 from t1 .
display-table-info. display "Elements: " t1 ", using " length(table-one) " bytes" display table-one .
end program array-length.</lang>
- Output:
$ cobc -xjd array-length.cob Elements: 02, using 000000014 bytes apples oranges
ColdFusion
<lang coldfusion> <cfset testArray = ["apple","orange"]> <cfoutput>Array Length = #ArrayLen(testArray)#</cfoutput> </lang>
Outputs:
Array Length = 2
Mike Knapp 15:57, 26 May 2016 (UTC)
Common Lisp
<lang Lisp> (print (length #("apple" "orange"))) </lang>
Alternate solution
I use Allegro CL 10.1
<lang lisp>
- Project
- Array length
(setf my-array (make-array '(2))) (setf (aref my-array 0) "apple") (setf (aref my-array 1) "orange") (format t "~a" "length of my-array: ") (length my-array) (terpri) </lang> Output:
length of my-array: 2
Component Pascal
<lang oberon2> MODULE AryLen; IMPORT StdLog;
TYPE String = POINTER TO ARRAY OF CHAR; VAR a: ARRAY 16 OF String;
PROCEDURE NewString(s: ARRAY OF CHAR): String; VAR str: String; BEGIN NEW(str,LEN(s$) + 1);str^ := s$; RETURN str END NewString;
PROCEDURE Length(a: ARRAY OF String): INTEGER; VAR i: INTEGER; BEGIN i := 0; WHILE a[i] # NIL DO INC(i) END; RETURN i END Length;
PROCEDURE Do*; BEGIN a[0] := NewString("Apple"); a[1] := NewString("Orange"); StdLog.String("Length:> ");StdLog.Int(Length(a));StdLog.Ln END Do;
END AryLen. </lang> Execute: ^Q AryLen.Do
- Output:
Length:> 2
Crystal
<lang ruby> puts ["apple", "orange"].size </lang>
- Output:
2
D
<lang d> import std.stdio;
int main() {
auto fruit = ["apple", "orange"]; fruit.length.writeln; return 0;
} </lang>
Or a somewhat shorter... <lang d> import std.stdio;
void main() {
["apple", "orange"].length.writeln;
} </lang>
Dart
<lang dart> arrLength(arr) {
return arr.length;
}
main() {
var fruits = ['apple', 'orange']; print(arrLength(fruits));
}
</lang>
Dragon
<lang dragon>select "std"
a = ["apple","orange"] b = length(a)
show b </lang>
DWScript
<lang delphi> var a := ['apple', 'orange']; PrintLn(a.Length); </lang>
Easyprog.online
<lang>fruit$[] = [ "apples" "oranges" ] print len fruit$[]</lang>
EchoLisp
<lang scheme> (length '("apple" "orange")) ;; list
→ 2
(vector-length #("apple" "orange")) ;; vector
→ 2
</lang>
Ela
<lang ela>length [1..10]</lang>
Elena
ELENA 4.x : <lang elena> var length := new string[]{"apple", "orange"}.Length; </lang>
Elixir
<lang elixir>iex(1)> length( ["apple", "orange"] ) # List 2 iex(2)> tuple_size( {"apple", "orange"} ) # Tuple 2</lang>
Elm
<lang elm> import Array import Html
main : Html.Html main =
["apple", "orange"] |> Array.fromList |> Array.length |> Basics.toString |> Html.text
</lang>
Emacs Lisp
<lang Lisp>(length ["apple" "orange"]) => 2</lang>
length
also accepts a list or a string.
Erlang
<lang Erlang> 1> length(["apple", "orange"]). %using a list 2 1> tuple_size({"apple", "orange"}). %using a tuple 2 </lang>
F#
<lang fsharp>[|1;2;3|].Length |> printfn "%i"</lang> Or: <lang fsharp>[|1;2;3|] |> Array.length |> printfn "%i"</lang>
Factor
<lang factor> { "apple" "orange" } length </lang>
Forth
The philosophy of Chuck Moore, the creator of Forth was that he did not want to write code for something he may never use. His solution was to distill his language into a large set of very simple routines that control the hardware directly. This demonstration must build "arrays" from scratch. In Forth, like in Assembler, you can do this any way you want. This demonstration adds new words to Forth that make a syntax to create simple variable length string arrays. Each string is a counted string with no trailing zero.
The code is commented to explain what is going on for those unfamiliar with Forth.
<lang>: STRING, ( caddr len -- ) \ Allocate space & compile string into memory
HERE OVER CHAR+ ALLOT PLACE ;
- " ( -- ) [CHAR] " PARSE STRING, ; \ Parse input to " and compile to memory
\ Array delimiter words
- { ALIGN 0 C, ; \ Compile 0 byte start/end of array
- } ALIGN 0 C, ;
\ String array words
- {NEXT} ( str -- next_str) \ Iterate to next string
COUNT + ;
- {NTH} ( n array_addr -- str) \ Returns address of the Nth item in the array
SWAP 0 DO {NEXT} LOOP ;
- {LEN} ( array_addr -- n) \ count strings in the array
0 >R \ Counter on Rstack {NEXT} BEGIN DUP C@ \ Fetch length byte WHILE \ While true R> 1+ >R \ Inc. counter {NEXT} REPEAT DROP R> ; \ return counter to data stack </lang>
Test code at Forth console <lang forth>CREATE Q { " Apples" " Oranges" } q {len} . 2 ok</lang>
Fortran
Early fortrans offered no protocol for ascertaining the length (or dimensionality) of arrays, though the compiler has this information. Thus a statement such as PRINT A
would print all the elements of a variable A
according to its definition. A subprogram that received a parameter would have no access to these details, so its parameter might be declared as A(12345)
simply to signify that it was an array (rather than an ordinary variable) and the programmer would rely on other data to know the upper bound to employ, for instance via an additional parameter. Any mistakes would cause crashes! On the other hand, with heavy computational tasks, it was common to take advantage of the opportunities. Thus, a subprogram might regard its array parameter as one-dimensional even though the actual parameter was not. Carefully-programmed routines might thusly process a sequence of elements via 1-D indexing, far faster than the 2-D or higher order indexing of the original. Success at this game required understanding how array elements were arranged in multidimensional arrays.
Later fortrans allowed A(*)
to signify an array parameter of unstated upper bound, but there was still a problem with higher dimensions. All but the last dimension has to be stated correctly if a multi-dimensional array parameter is to be indexed correctly - Fortran stores array elements in column-major order.
With Fortran 90, a new protocol was introduced, whereby the parameter might be declared as A(:)
signifying an array of one dimension, of bounds unstated. A 2-D array would have A(:,:)
and so on. Further, arrays could have arbitrary lower bounds as well, as in A(-7:12)
but if no colon appeared for a dimension, the lower bound would be assumed to be one so A(2)
means an array of two elements, as before. And as before, in a subprogram a bound could be explicitly stated, perhaps via an explicit parameter such as N
, but now with the :
scheme, the compiler is passing secret additional parameters to the subprogram giving the bounds of the array, and these can be accessed via the library functions LBOUND and UBOUND. For multi-dimensional arrays there are multiple bounds, and an invocation might be UBOUND(A,DIM = 2)
but in the example only a one-dimensional array is involved. These facilities are available only if the new MODULE protocol is employed.
The task is in terms of an array holding the texts "Apple" and "Orange", so a CHARACTER*6 element size will do; the subprogram receives yet another secret parameter specifying the size of CHARACTER parameters. This size can be accessed via the LEN function, and, since in principle the index span is arbitrary, no constant index is sure to be a valid index of some single element: thus the LBOUND function is used to finger one that is.
For a simple example, the WRITE(6,*) suffices: write to standard output (the 6), in free-format (the *).
<lang Fortran>
MODULE EXAMPLE CONTAINS SUBROUTINE ABOUND(A) CHARACTER*(*) A(:) !One dimensional array, unspecified bounds. WRITE (6,*) "Lower bound",LBOUND(A),", Upper bound",UBOUND(A) WRITE (6,*) "Element size",LEN(A(LBOUND(A))) WRITE (6,*) A END SUBROUTINE ABOUND END MODULE EXAMPLE
PROGRAM SHOWBOUNDS USE EXAMPLE CHARACTER*6 ARRAY(-1:1) ARRAY(-1) = "Apple" ARRAY(0) = "Orange" ARRAY(1) = "" CALL ABOUND(ARRAY) WRITE (6,*) "But, when it is at home..." WRITE (6,*) "L. bound",LBOUND(ARRAY),", U. bound",UBOUND(ARRAY) END
</lang>
Output:
Lower bound 1 , Upper bound 3 Element size 6 Apple Orange But, when it is at home... L. bound -1 , U. bound 1
Notice that the subprogram sees the array as an old-style array starting with index one! If it is to work with a lower bound other than one, the declaration in the subprogram must state it, perhaps as A(-1:) or as A(START:), etc. The upper bound remains unspecified, and with that declaration, UBOUND returns 1 instead of 3, corresponding to the shift. Thus, UBOUND returns not the actual upper bound of the array parameter (as supplied) but the upper bound relative to the lower bound in use in the subprogram so that UBOUND - LBOUND + 1 does give the number of elements.
If in the subprogram the bounds are fixed (say as A(-1:6)
) then a CALL ABOUND(ARRAY) may provoke a compiler complaint if ARRAY is not a suitable size.
FreeBASIC
<lang freebasic>' FB 1.05.0 Win64
Dim fruit(1) As String = {"apple", "orange"} Dim length As Integer = UBound(fruit) - LBound(fruit) + 1 Print "The length of the fruit array is"; length Print Print "Press any key to quit the program" Sleep</lang>
- Output:
The length of the fruit array is 2
Frink
<lang frink> a = ["apple", "orange"] println[length[a]] </lang>
FurryScript
<lang furryscript>THE_LIST( <apple> <orange> ) COUNT[ 0 SW ~| COUNT_STEP# 0 SW SU ] COUNT_STEP[ DR 1 SU ]
`THE_LIST COUNT# +<></lang>
Futhark
The shape
builtin returns the shape of an array as an array of integers. The length is element 0 of the shape:
<lang Futhark> fun length(as: []int): int = (shape as)[0] </lang>
FutureBasic
<lang futurebasic> include "ConsoleWindow"
dim as CFArrayRef array dim as Str255 s dim as CFStringRef fruits, tempStr dim as CFIndex ubound, i
fruits = @"apples,bananas,cherries,dates,grapes,lemon,lime,orange,peach,pear,pineapple,strawberries,watermelon" array = fn CFStringCreateArrayBySeparatingStrings( _kCFAllocatorDefault, fruits, @"," )
ubound = fn CFArrayGetCount( array ) for i = 0 to ubound - 1
tempStr = fn CFArrayGetValueAtIndex( array, i ) fn CFStringGetPascalString( tempStr, @s, 256, _kCFStringEncodingMacRoman ) CFRelease( tempStr ) print "Fruit"; i; " = "; s
next </lang> Output:
Fruit 0 = apples Fruit 1 = bananas Fruit 2 = cherries Fruit 3 = dates Fruit 4 = grapes Fruit 5 = lemon Fruit 6 = lime Fruit 7 = orange Fruit 8 = peach Fruit 9 = pear Fruit 10 = pineapple Fruit 11 = strawberries Fruit 12 = watermelon
Gambas
Click this link to run this code <lang gambas>Public Sub Main() Dim siList As Short[] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
Print siList.Count
End</lang> Output:
10
Go
<lang Go>package main
import "fmt"
func main() { arr := [...]string{"apple", "orange", "pear"}
fmt.Printf("Length of %v is %v.\n", arr, len(arr)) }</lang>
Groovy
<lang Groovy> def fruits = ['apple','orange'] println fruits.size() </lang>
Haskell
<lang Haskell>-- Char -> Int length ["apple", "orange"]</lang>
hexiscript
<lang hexiscript>let a arr 2 let a[0] "apple" let a[1] "orange" println len a</lang>
i
<lang i>software { print(#["apple", "orange"]) }</lang>
Idris
<lang Idris>length ["apple", "orange"]</lang>
J
Tally (#
) returns the length of the leading dimension of an array (or 1 if the array has no dimensions). Shape Of ($
) returns the length of each dimension of an array.
<lang j> # 'apple';'orange'
2
$ 'apple';'orange'
2</lang> For the list array example given, the result appears to be the same. The difference is that the result of Tally is a scalar (array of 0 dimensions) whereas the result of Shape Of is a list (1 dimensional array), of length 1 in this case. <lang j> $#'apple';'orange'
$$'apple';'orange'
1</lang> This might be a clearer concept with a few more examples. Here's an array with two dimensions: <lang j> >'apple';'orange' apple orange
$>'apple';'orange'
2 6
#>'apple';'orange'
2</lang> And, here's an array with no dimensions: <lang> 9001 9001
#9001
1
$9001
</lang>
You can count the number of dimensions of an array (the length of the list of lengths) using #$array
:
<lang j>
#$9001
0
#$'apple';'orange'
1
#$>'apple';'orange'
2</lang>
Java
<lang java>public class ArrayLength {
public static void main(String[] args) { System.out.println(new String[]{"apple", "orange"}.length); }
}</lang>
JavaScript
<lang javascript>console.log(['apple', 'orange'].length);</lang>
However, determining the length of a list, array, or collection may simply be the wrong thing to do.
If, for example, the actual task (undefined here, unfortunately) requires retrieving the final item, while it is perfectly possible to write last in terms of length
<lang JavaScript>function last(lst) {
return lst[lst.length - 1];
}</lang>
using length has the disadvantage that it leaves last simply undefined for an empty list.
We might do better to drop the narrow focus on length, and instead use a fold (reduce, in JS terms) which can return a default value of some kind.
<lang JavaScript>function last(lst) {
return lst.reduce(function (a, x) { return x; }, null);
}</lang>
Alternatively, rather than scanning the entire list to simply get the final value, it might sometimes be better to test the length:
<lang JavaScript>function last(list, defaultValue) {
return list.length ?list[list.length-1] :defaultValue;
}</lang>
Or use other built-in functions – this, for example, seems fairly clear, and is already 100+ times faster than unoptimised tail recursion in ES5 (testing with a list of 1000 elements):
<lang JavaScript>function last(list, defaultValue) {
return list.slice(-1)[0] || defaultValue;
}</lang>
jq
<lang jq>["apple","orange"] | length</lang> Output: <lang sh>2</lang>
Note that the length filter is polymorphic, so for example the empty string (""), the empty list ([]), and null all have length 0.
Julia
<lang Julia> a = ["apple","orange"] length(a) </lang>
Klong
<lang K>
- ["apple" "orange"]
</lang>
Kotlin
<lang scala>fun main(args: Array<String>) {
println(arrayOf("apple", "orange").size)
}</lang>
Latitude
In Latitude, length
and size
are synonymous and will both retrieve the size of a collection.
<lang latitude>println: ["apple", "orange"] length.</lang>
Liberty BASIC
When a one or two dimensional array, A$, with subscript(s) of 10 or less is referenced (either by assigning or reading), the compiler does an implicit DIM A$(10) or DIM A$(10,10). Before referencing an array with any subscript numbered higher than 10, or arrays of three dimensions or more, the programmer must first issue an explicit DIM statement.
There is no function in Liberty Basic to directly read the size of an array. This program uses error trapping loops to, first, determine the number of dimensions of the array. Then, second, again uses error trapping loops to determine the number of elements in each dimension. Finally, it prints the DIM statement that was used to define the array.
I suppose the implicit DIM feature makes it a bit quicker to write short, simple programs. One or two dimension arrays may be resized with REDIM. Three dimension or more arrays can not be resized. All arrays may be cleared with REDIM. Keep in mind that A$(n) and A$(n,m) are the same array. You must refer to it with the correct arguments or get an error.
NOTE -- This program runs only under LB Booster version 3.05 or higher because of arrays with more than two dimensions, passed array names to functions and subroutines as a parameter, and structured error trapping syntax. Get the LBB compiler here: http://lbbooster.com/
<lang lb> FruitList$(0)="apple" 'assign 2 cells of a list array FruitList$(1)="orange" dimension=dimension(FruitList$()) 'first get the dimension of the array if dimension>3 then
print "Sorry, program only written for array dimensions of 3 or less." end
end if call elements FruitList$(), dimension 'next get the size of each dimension end
function dimension(array$())
for dimension=1 to 4 select case dimension case 1 try: x$=array$(0) catch: goto [TryNext] end try exit for case 2 try: x$=array$(0,0) catch: goto [TryNext] end try exit for case 3 try: x$=array$(0,0,0) catch: goto [TryNext] end try exit for case 4 exit for end select [TryNext] next dimension if dimension<4 then print "array dimension = "; dimension ArraySize(0)=dimension
end function
sub elements array$(), dimension
select case dimension case 1 try do x$=array$(a) a+=1 loop catch: elements=a end try ArraySize(1)=elements-1 print "dimension 1 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(1) case 2 try do x$=array$(a,0) a+=1 loop catch: elements=a end try ArraySize(1)=elements-1 print "dimension 1 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(1) elements=0 try do x$=array$(0,b) b+=1 loop catch: elements=b end try ArraySize(2)=elements-1 print "dimension 2 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(2) case 3 try do x$=array$(a,0,0) a+=1 loop catch: elements=a end try ArraySize(1)=elements-1 print "dimension 1 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(1) elements=0 try do x$=array$(0,b,0) b+=1 loop catch: elements=b end try ArraySize(2)=elements-1 print "dimension 2 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(2) elements=0 try do x$=array$(0,0,c) c+=1 loop catch: elements=c end try ArraySize(3)=elements-1 print "dimension 3 has "; elements; " elements (cells), "_ "numbered 0 to "; ArraySize(3) end select 'print the explicit or implied DIMension statement for this array print "DIM array$("; a-1; if b>0 then print ","; b-1; if c>0 then print ","; c-1; print ")"
end sub </lang>
- Output:
array dimension = 1 dimension 1 has 11 elements (cells), numbered 0 to 10 DIM array$(10)
Limbo
<lang Limbo>implement Command;
include "sys.m"; sys: Sys;
include "draw.m";
include "sh.m";
init(nil: ref Draw->Context, nil: list of string) { sys = load Sys Sys->PATH;
a := array[] of {"apple", "orange"}; sys->print("length of a: %d\n", len a); }</lang>
Lingo
<lang lingo>fruits = ["apple", "orange"] put fruits.count -- 2</lang>
Little
<lang C>string fruit[] = {"apples", "oranges"}; puts(length(fruit));</lang>
LiveCode
<lang LiveCode>put "apple","orange" into fruit split fruit using comma answer the number of elements of fruit</lang>
Lua
<lang Lua>-- For tables as simple arrays, use the # operator: fruits = {"apple", "orange"} print(#fruits)
-- Note the # symbol does not work for non-integer-indexed tables: fruits = {fruit1 = "apple", fruit2 = "orange"} print(#fruits)
-- For this you can use this short function: function size (tab)
local count = 0 for k, v in pairs(tab) do count = count + 1 end return count
end
print(size(fruits))</lang>
- Output:
2 0 2
M2000 Interpreter
<lang M2000 Interpreter> \\ A is a pointer to array A=("Apple", "Orange") Print Len(A)=2 ' True Print Dimension(A, 0) ' LBound (0 or 1), here 0 Print Dimension(A) ' No of Dimensions 1 Print Dimension(A, 1) ' for 1 dimension array this is also Length=2 \\ A$( ) is an Array (not a pointer to array) Dim Base 1, A$(2) A$(1)="Apple", "Orange" Print Dimension(A$(), 0) ' LBound (0 or 1), here 1 Print Dimension(A$()) ' No of Dimensions 1 Print Dimension(A$(), 1) ' for 1 dimension array this is also Length=2 Link A to B$() ' B$() is a reference to A Print B$(0)=A$(1) Print B$(1)=A$(2) Dim C$() \\ C$() get a copy of B$() C$()=B$() Print C$() ' prints Apple Orange \\ An array can link to a new name as reference, and can change major type \\ here A$() get A() so we can read/store numbers and read/store strings in same array \\ using two names Link A$() to A() \\ An array pointer can point to another array A=A() Print Dimension(A, 0) ' LBound (0 or 1), here 1 (was 0) \\ Because B$() is reference of A: Print Dimension(B$(), 0) ' LBound (0 or 1), here 1 (was 0) Print B$(1)=A$(1) Print B$(2)=A$(2) Print Dimension(C$(), 0) ' LBound (0 or 1), here 0 \\ change base preserve items Dim Base 1, C$(Dimension(C$(), 1)) Print Dimension(C$(), 0) ' LBound (0 or 1), here 1 (was 0) Print C$() ' prints Apple Orange Print Len(C$()) ' Len return all items of an array - can be 0 Dim K(1,1,1,1,1,1) ' Maximum 10 dimensions Print Len(K()=1 ' True </lang>
Maple
<lang maple>a := Array(["apple", "orange"]); numelems(a);</lang>
- Output:
a := [ "apple" "orange" ] 2
Mathematica
<lang Mathematica>Length[{"apple", "orange"}]</lang>
MATLAB / Octave
<lang Matlab>length({'apple', 'orange'})</lang> For arrays with more than one dimension, length reports the length of the larges dimension. The number of elements in a multi-dimensional array can be obtained with numel. <lang Matlab>numel({'apple', 'orange'; 'pear', 'banana'})</lang>
min
<lang min>("apple" "orange") size print</lang>
- Output:
2
Nanoquery
<lang nanoquery>$fruit = array(2) $fruit[0] = "apple" $fruit[1] = "orange" println len($fruit)
// outputs 2</lang>
Neko
<lang neko>var fruit = $array("apple", "orange");
$print($asize(fruit));</lang>
NewLISP
<lang newlisp>(println (length '("apple" "orange")))
- Nehal-Singhal 2018-05-25
(length '(apple orange))</lang>
NGS
<lang NGS>echo(len(['apple', 'orange']))
- same
echo(['apple', 'orange'].len())</lang>
Nim
<lang nim>let fruit = ["apple", "orange"] echo "The length of the fruit array is ", len(fruit)</lang>
- Output:
The length of the fruit array is 2
Oberon-2
<lang oberon2> MODULE ArrayLength; IMPORT
Strings, Out;
TYPE
String = POINTER TO ARRAY OF CHAR;
VAR
a: ARRAY 16 OF String;
PROCEDURE NewString(s: ARRAY OF CHAR): String; VAR
str: String;
BEGIN
NEW(str,Strings.Length(s) + 1);COPY(s,str^); RETURN str
END NewString;
PROCEDURE Length(a: ARRAY OF String): LONGINT; VAR
i: LONGINT;
BEGIN
i := 0; WHILE (a[i] # NIL) DO INC(i) END; RETURN i;
END Length;
BEGIN
a[0] := NewString("apple"); a[1] := NewString("orange"); Out.String("length: ");Out.Int(Length(a),0);Out.Ln
END ArrayLength. </lang>
- Output:
length: 2
Objeck
<lang objeck> class Test {
function : Main(args : String[]) ~ Nil { fruit := ["apples", "oranges"]; fruit->Size()->PrintLine(); }
}</lang>
OCaml
<lang OCaml> Array.length [|"apple"; "orange"|];; </lang>
Oforth
<lang Oforth>[ "apple", "orange" ] size</lang>
Onyx
<lang onyx>[`apple' `orange'] length # leaves 2 on top of the stack</lang>
ooRexx
<lang oorexx> /* REXX */ a = .array~of('apple','orange') say a~size 'elements' Do e over a
say e End
Say "a[2]="a[2]</lang>
- Output:
2 elements apple orange a[2]=orange
PARI/GP
<lang parigp>array = ["apple", "orange"] length(array) \\ == 2
- array \\ == 2</lang>
The #
syntax is a handy shorthand. It usually looks best just on variables but it works on expressions too, possibly with parens to control precedence.
Both forms work on column vectors too, and also on strings and matrices. (For a matrix it is the number of columns.)
Pascal
<lang Pascal>
- !/usr/bin/instantfpc
//program ArrayLength;
{$mode objfpc}{$H+}
uses SysUtils, Classes;
const
Fruits : array[0..1] of String = ('apple', 'orange');
begin
WriteLn('Length of Fruits by function : ', Length(Fruits)); WriteLn('Length of Fruits by bounds : ', High(Fruits) - Low(Fruits) + 1);
END. </lang>
- Output:
./ArrayLength.pas Length of Fruits by function : 2 Length of Fruits by bounds : 2
Perl
The way to get the number of elements of an array in Perl is to put the array in scalar context.
<lang perl>my @array = qw "apple orange banana", 4, 42;
scalar @array; # 5 0 + @arrray; # 5 . @array; # "5" my $elems = @array; # $elems = 5
scalar @{ [1,2,3] }; # [1,2,3] is a reference which is already a scalar
my $array_ref = \@array; # a reference scalar @$array_ref;
- using subroutine prototypes, not generally recommended
- and not usually what you think they are
sub takes_a_scalar ($) { my ($a) = @_; return $a }
takes_a_scalar @array;
- the built-ins can also act like they have prototypes</lang>
A common mistake is to use length
which works on strings not arrays.
So using it on an array, as a side-effect, actually gives you a number which represents the order of magnitude.
<lang perl6>length . @array; # 1 length @array; # 1
print '0.', scalar @array, 'e', length @array, "\n"; # 0.5e1
@array = 1..123; print '0.', scalar @array, 'e', length @array, "\n"; # 0.123e3
print 'the length of @array is on the order of '; print 10 ** (length( @array )-1); # 100 print " elements long\n";</lang>
Perl 6
To get the number of elements of an array in Perl 6 you put the array in a coercing Numeric context, or call elems
on it.
<lang perl6> my @array = <apple orange>;
say @array.elems; # 2 say elems @array; # 2 say + @array; # 2 say @array + 0; # 2 </lang>
Watch out for infinite/lazy arrays though. You can't get the length of those.
<lang perl6>my @infinite = 1 .. Inf; # 1, 2, 3, 4, ...
say @infinite[5000]; # 5001 say @infinite.elems; # Throws exception "Cannot .elems a lazy list" </lang>
Phix
<lang Phix>constant fruits = {"apple","orange"} ?length(fruits)</lang>
- Output:
2
PHP
<lang php>print count(['apple', 'orange']); // Returns 2</lang>
PicoLisp
<lang PicoLisp>: (length '(apple orange)) -> 2
- </lang>
Pike
<lang pike>void main() {
array fruit = ({ "apple", "orange" }); write("%d\n", sizeof(fruit));
}</lang>
- Output:
2
PL/I
<lang pli> p: Proc Options(main);
Dcl a(2) Char(6) Init('apple','orange'); Put Edit('Array a has',(hbound(a)-lbound(a)+1),' elements.') (Skip,a,f(2),a); Put Skip Data(a); End;</lang>
- Output:
Array a has 2 elements. A(1)='apple ' A(2)='orange';
Plorth
<lang plorth>["apple", "orange"] length println</lang>
Pony
<lang pony> actor Main
new create(env:Env)=> var c=Array[String](2) c.push("apple") c.push("orange") env.out.print("Array c is " + c.size().string() + " elements long!")
</lang>
Potion
<lang potion>("apple", "orange") length print</lang>
PowerShell
<lang PowerShell> $Array = @( "Apple", "Orange" ) $Array.Count $Array.Length</lang>
- Output:
2 2
Processing
<lang Processing> String[] arr = {"apple", "orange"}; void setup(){
println(arr.length);
} </lang>
- Output:
2
Prolog
<lang Prolog>| ?- length(["apple", "orange"], X).
X = 2
yes</lang>
PureBasic
<lang PureBasic> EnableExplicit Define Dim fruit$(1); defines array with 2 elements at indices 0 and 1 fruit$(0) = "apple" fruit$(1) = "orange" Define length = ArraySize(fruit$()) + 1; including the element at index 0 If OpenConsole()
PrintN("The length of the fruit array is " + length) PrintN("") PrintN("Press any key to close the console") Repeat: Delay(10) : Until Inkey() <> "" CloseConsole()
EndIf </lang>
Python
<lang python>>>> print(len(['apple', 'orange'])) 2 >>> </lang>
R
<lang R> a <- c('apple','orange') # create a vector containing "apple" and "orange" length(a) </lang>
- Output:
[1] 2
Racket
<lang racket>#lang racket/base (length '("apple" "orange")) ;; list (vector-length #("apple" "orange")) ;; vector</lang>
- Output:
2 2
Red
<lang Red>length? ["apples" "oranges"] == 2</lang>
REXX
<lang rexx>/* REXX ----------------------------------------------
- The compond variable a. implements an array
- By convention, a.0 contains the number of elements
- ---------------------------------------------------*/
a.=0 /* initialize the "array" */ call store 'apple' Call store 'orange' Say 'There are' a.0 'elements in the array:' Do i=1 To a.0
Say 'Element' i':' a.i End
Exit store: Procedure Expose a. z=a.0+1 a.z=arg(1) a.0=z Return</lang>
- Output:
There are 2 elements in the array: Element 1: apple Element 2: orange
Ring
<lang ring>See len(['apple', 'orange']) # output = 2 </lang>
Ruby
<lang ruby>puts ['apple', 'orange'].length # or .size</lang>
Rust
By default arrays are immutable in rust.
<lang rust> fn main() {
let array = ["foo", "bar", "baz", "biff"]; println!("the array has {} elements", array.len());
} </lang>
Scala
<lang scala> println(Array("apple", "orange").length) </lang>
Scheme
Using Scheme's vector type as an equivalent to an array:
<lang scheme> (display (vector-length #("apple" "orange"))) </lang>
Seed7
The function length determines the length of an array. <lang seed7>$ include "seed7_05.s7i";
const array string: anArray is [] ("apple", "orange");
const proc: main is func
begin writeln(length(anArray)); end func;</lang>
SETL
<lang haskell> arr := ["apple", "orange"]; print(# arr); -- '#' is the cardinality operator. Works on strings, tuples, and sets. </lang>
Sidef
<lang ruby>var arr = ['apple', 'orange']; say arr.len; #=> 2 say arr.end; #=> 1 (zero based)</lang>
Simula
<lang simula>COMMENT ARRAY-LENGTH; BEGIN
INTEGER PROCEDURE ARRAYLENGTH(A); TEXT ARRAY A; BEGIN ARRAYLENGTH := UPPERBOUND(A, 1) - LOWERBOUND(A, 1) + 1; END ARRAYLENGTH;
TEXT ARRAY A(1:2); INTEGER L; A(1) :- "APPLE"; A(2) :- "ORANGE"; L := ARRAYLENGTH(A); OUTINT(L, 0); OUTIMAGE;
END </lang>
- Output:
2
Smalltalk
<lang smalltalk> a := #('apple' 'orange'). a size</lang>
SNOBOL4
<lang SNOBOL4> ar = ARRAY('2,2')
ar<1,1> = 'apple' ar<1,2> = 'first' ar<2,1> = 'orange' ar<2,2> = 'second' OUTPUT = IDENT(DATATYPE(ar), 'ARRAY') PROTOTYPE(ar)
end</lang>
- Output:
2,2
SPL
<lang spl>a = ["apple","orange"]
- .output("Number of elements in array: ",#.size(a,1))</lang>
- Output:
Number of elements in array: 2
SQL
<lang sql>SELECT COUNT() FROM (VALUES ('apple'),('orange'));</lang>
Standard ML
<lang sml>let
val a = Array.fromList ["apple", "orange"]
in
Array.length a
end;</lang>
Stata
String data may be stored either in a Stata dataset or in a Mata matrix, not in a Stata matrix, which may hold only numeric data. A list of strings may also be stored in a Stata macro.
Dimensions of a dataset
<lang stata>clear input str10 fruit apple orange end
di _N di c(N) " " c(k)</lang>
Length of a macro list
Use either the sizeof macro list function or the word count extended macro function. Notice that the argument of the former is the macro name, while the argument of the latter is the macro contents.
<lang stata>local fruits apple orange di `: list sizeof fruits' di `: word count `fruits</lang>
Mata
For a Mata array, use rows and similar functions:
<lang stata>mata a=st_sdata(.,"fruit") rows(a) cols(a) length(a) end</lang>
Swift
<lang Swift>import Cocoa //include Cocoa library (standard in OS X)
let fruits = ["apple", "orange"] //declare constant array literal let fruitsCount = fruits.count //declare constant array length (count)
print(fruitsCount) //print array length to output window</lang>
- Output:
2
Tcl
<lang tcl>;# not recommanded: set mylistA {apple orange} ;# actually a string set mylistA "Apple Orange" ;# same - this works only for simple cases
set lenA [llength $mylistA] puts "$mylistA : $lenA"
- better: to build a list, use 'list' and/or 'lappend':
set mylistB [list apple orange "red wine" {green frog}] lappend mylistB "blue bird"
set lenB [llength $mylistB] puts "$mylistB : $lenB" </lang>
- Output:
Apple Orange : 2 apple orange {red wine} {green frog} {blue bird} : 5
TI-83 BASIC
Use function dim()
.
<lang ti83b>{1,3,–5,4,–2,–1}→L1
dim(L1)</lang>
- Output:
6
UNIX Shell
<lang bash>#!/bin/bash array=("orange" "apple") echo "${#array[@]}"</lang>
- Output:
2
Ursa
> decl string<> stream > append "two" "strings" stream > out (size stream) endl console 2 > out (size "test string") endl console 11 >
VBA
<lang vb>Debug.Print "Array Length: " & UBound(Array("apple", "orange")) + 1</lang>
- Output:
Array Length: 2
VBScript
<lang vb>arr = Array("apple","orange") WScript.StdOut.WriteLine UBound(arr) - LBound(arr) + 1 </lang>
- Output:
2
Visual Basic
The amount of elements in an array in Visual Basic is computed via the upper bound and lower bound indices. In Visual Basic the indices of arrays have to be numeric, but it is even possible to have negative values for them. Of course the element numbering is continuous.
<lang vb> ' declared in a module Public Function LengthOfArray(ByRef arr As Variant) As Long
If IsArray(arr) Then LengthOfArray = UBound(arr) - LBound(arr) + 1 Else LengthOfArray = -1 End If
End Function
' somewhere in the programm ' example 1
Dim arr As Variant arr = Array("apple", "orange") Debug.Print LengthOfArray(arr) ' prints 2 as result
' example 2
Dim arr As Variant ReDim arr(-2 To -1) arr(-2) = "apple" arr(-1) = "orange"
Debug.Print LengthOfArray(arr) ' prints 2 as result
</lang>
WDTE
<lang wdte>let io => import 'io'; let a => ['apple'; 'orange']; len a -- io.writeln io.stdout;</lang>
Wren
<lang wren>var arr = [1,2,3] var length = arr.count </lang>
XLISP
<lang lisp>(vector-length #("apple" "orange"))</lang>
zkl
zkl doesn't support arrays natively, use lists instead. <lang zkl>List("apple", "orange").len().println() //-->2, == L("apple", "orange") T("apple", "orange").len().println() //-->2, read only list (ROList) </lang>
zonnon
<lang zonnon> module AryLength; type Vector = array 12 of string; Matrix = array *,* of string; var a: Vector; b: Matrix; begin writeln(len(a):4); (* len(a) = len(a,0) *)
b := new Matrix(10,11); writeln(len(b,0):4); (* first dimension *) writeln(len(b,1):4) (* second dimension *) end AryLength. </lang>
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