Array concatenation

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Task
Array concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Show how to concatenate two arrays in your language. If this is as simple as array1 + array2, so be it.

Contents

[edit] ACL2

This is for lists, not arrays; ACL2's array support is limited.

(append xs ys)

[edit] ActionScript

var array1:Array = new Array(1, 2, 3);
var array2:Array = new Array(4, 5, 6);
var array3:Array = array1.concat(array2); //[1, 2, 3, 4, 5, 6]

[edit] Ada

In Ada arrays are concatenated using the operation &. It works with any one dimensioned array:

type T is array (Positive range <>) of Integer;
X : T := (1, 2, 3);
Y : T := X & (4, 5, 6); -- Concatenate X and (4, 5, 6)

[edit] ALGOL 68

Works with: ALGOL 68 version Standard - no extensions to language used
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny

Includes operators for appending and prefixing an array to an existing flexible array:

MODE ARGTYPE = INT;
MODE ARGLIST = FLEX[0]ARGTYPE;
 
OP + = (ARGLIST a, b)ARGLIST: (
[LWB a:UPB a - LWB a + 1 + UPB b - LWB b + 1 ]ARGTYPE out;
(
out[LWB a:UPB a]:=a,
out[UPB a+1:]:=b
);
out
);
 
# Append #
OP +:= = (REF ARGLIST lhs, ARGLIST rhs)ARGLIST: lhs := lhs + rhs;
OP PLUSAB = (REF ARGLIST lhs, ARGLIST rhs)ARGLIST: lhs := lhs + rhs;
 
# Prefix #
OP +=: = (ARGLIST lhs, REF ARGLIST rhs)ARGLIST: rhs := lhs + rhs;
OP PLUSTO = (ARGLIST lhs, REF ARGLIST rhs)ARGLIST: rhs := lhs + rhs;
 
ARGLIST a := (1,2),
b := (3,4,5);
 
print(("a + b",a + b, new line));
 
VOID(a +:= b);
print(("a +:= b", a, new line));
 
VOID(a +=: b);
print(("a +=: b", b, new line))
a + b         +1         +2         +3         +4         +5
a +:= b         +1         +2         +3         +4         +5
a +=: b         +1         +2         +3         +4         +5         +3         +4         +5

[edit] APL

 
1 2 3 , 4 5 6
1 2 3 4 5 6
 

[edit] AutoHotkey

[edit] True Arrays

Works with: AutoHotkey_L
List1 := [1, 2, 3]
List2 := [4, 5, 6]
cList := Arr_concatenate(List1, List2)
MsgBox % Arr_disp(cList) ; [1, 2, 3, 4, 5, 6]
 
Arr_concatenate(p*) {
res := Object()
For each, obj in p
For each, value in obj
res.Insert(value)
return res
}
 
Arr_disp(arr) {
for each, value in arr
res .= ", " value
return "[" SubStr(res, 3) "]"
}

[edit] Legacy versions

AutoHotkey_Basic does not have real Arrays, but the user can implement them quite easily. For example:

List1 = 1,2,3
List2 = 4,5,6
 
List2Array(List1 , "Array1_")
List2Array(List2 , "Array2_")
 
ConcatArrays("Array1_", "Array2_", "MyArray")
MsgBox, % Array2List("MyArray")
 
 
;---------------------------------------------------------------------------
ConcatArrays(A1, A2, A3) { ; concatenates the arrays A1 and A2 to A3
;---------------------------------------------------------------------------
local i := 0
%A3%0 := %A1%0 + %A2%0
Loop, % %A1%0
i++, %A3%%i% := %A1%%A_Index%
Loop, % %A2%0
i++, %A3%%i% := %A2%%A_Index%
}
 
 
;---------------------------------------------------------------------------
List2Array(List, Array) { ; creates an array from a comma separated list
;---------------------------------------------------------------------------
global
StringSplit, %Array%, List, `,
}
 
 
;---------------------------------------------------------------------------
Array2List(Array) { ; returns a comma separated list from an array
;---------------------------------------------------------------------------
Loop, % %Array%0
List .= (A_Index = 1 ? "" : ",") %Array%%A_Index%
Return, List
}

Message box shows:

1,2,3,4,5,6

[edit] AutoIt

_ArrayConcatenate is a standard function in Autoit, there´s no need to write it on your own


 
_ArrayConcatenate($avArray, $avArray2)
Func _ArrayConcatenate(ByRef $avArrayTarget, Const ByRef $avArraySource, $iStart = 0)
If Not IsArray($avArrayTarget) Then Return SetError(1, 0, 0)
If Not IsArray($avArraySource) Then Return SetError(2, 0, 0)
If UBound($avArrayTarget, 0) <> 1 Then
If UBound($avArraySource, 0) <> 1 Then Return SetError(5, 0, 0)
Return SetError(3, 0, 0)
EndIf
If UBound($avArraySource, 0) <> 1 Then Return SetError(4, 0, 0)
 
Local $iUBoundTarget = UBound($avArrayTarget) - $iStart, $iUBoundSource = UBound($avArraySource)
ReDim $avArrayTarget[$iUBoundTarget + $iUBoundSource]
For $i = $iStart To $iUBoundSource - 1
$avArrayTarget[$iUBoundTarget + $i] = $avArraySource[$i]
Next
 
Return $iUBoundTarget + $iUBoundSource
EndFunc ;==>_ArrayConcatenate
 

[edit] AWK

#!/usr/bin/awk -f
BEGIN {
split("cul-de-sac",a,"-")
split("1-2-3",b,"-")
concat_array(a,b,c)
 
for (i in c) {
print i,c[i]
}
}
 
function concat_array(a,b,c) {
for (i in a) {
c[++nc]=a[i]
}
for (i in b) {
c[++nc]=b[i]
}
}

[edit] Babel

main : { [val 1 2 3] [val 4 5 6] cat }

[edit] bash

x=("1  2" "3  4")
y=(5 6)
sum=( "${x[@]}" "${y[@]}" )
 
for i in "${sum[@]}" ; do echo "$i" ; done
1 2
3 4
5
6

[edit] BBC BASIC

      DIM a(3), b(4)
a() = 1, 2, 3, 4
b() = 5, 6, 7, 8, 9
PROCconcat(a(), b(), c())
 
FOR i% = 0 TO DIM(c(),1)
PRINT c(i%)
NEXT
END
 
DEF PROCconcat(a(), b(), RETURN c())
LOCAL s%, na%, nb%
s% = ^a(1) - ^a(0) : REM Size of each array element
na% = DIM(a(),1)+1 : REM Number of elements in a()
nb% = DIM(b(),1)+1 : REM Number of elements in b()
DIM c(na%+nb%-1)
SYS "RtlMoveMemory", ^c(0), ^a(0), s%*na%
SYS "RtlMoveMemory", ^c(na%), ^b(0), s%*nb%
ENDPROC

[edit] Bracmat

Bracmat concatenates lists composed with the comma, space, addition and multiplication operators. Furthermore, lists composed with the addition and multiplication operators are canonically sorted and like terms or factors are combined algebraically. Lists composed with the space operator automatically delete any elements with zero-length atoms and no prefixes. All these lists except the comma-separated list support a notion of 'array index', but as the underlying datastructure is a linked list and not an array, accessing, say, the millionth element can be slow. Examples of concatenation (entered on the Bracmat command line):

{?} (a,b,c,d,e),(n,m)
{!} a,b,c,d,e,n,m
{?} (a,m,y),(b,n,y,z)
{!} a,m,y,b,n,y,z
{?} (a m y) (b n y z)
{!} a m y b n y z
{?} (a+m+y)+(b+n+y+z)
{!} a+b+m+n+2*y+z
{?} (a*m*y)*(b*n*y*z)
{!} a*b*m*n*y^2*z

Concatenate three lists and split the concatenated list using a position operator:

{?} (a b c d) (e f g h) (i j k):?A [7 ?Z
{!} a b c d e f g h i j k
{?} !A
{!} a b c d e f g
{?} !Z
{!} h i j k

[edit] Burlesque

 
blsq ) {1 2 3}{4 5 6}_+
{1 2 3 4 5 6}
 

[edit] C

A way to concatenate two C arrays when you know their size (and usually so it is)

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
 
#define ARRAY_CONCAT(TYPE, A, An, B, Bn) \
(TYPE *)array_concat((const void *)(A), (An), (const void *)(B), (Bn), sizeof(TYPE));

 
void *array_concat(const void *a, size_t an,
const void *b, size_t bn, size_t s)
{
char *p = malloc(s * (an + bn));
memcpy(p, a, an*s);
memcpy(p + an*s, b, bn*s);
return p;
}
 
// testing
const int a[] = { 1, 2, 3, 4, 5 };
const int b[] = { 6, 7, 8, 9, 0 };
 
int main(void)
{
unsigned int i;
 
int *c = ARRAY_CONCAT(int, a, 5, b, 5);
 
for(i = 0; i < 10; i++)
printf("%d\n", c[i]);
 
free(c);
return EXIT_SUCCCESS;
}

[edit] C++

#include <vector>
#include <iostream>
 
int main()
{
std::vector<int> a(3), b(4);
a[0] = 11; a[1] = 12; a[2] = 13;
b[0] = 21; b[1] = 22; b[2] = 23; b[3] = 24;
 
a.insert(a.end(), b.begin(), b.end());
 
for (int i = 0; i < a.size(); ++i)
std::cout << "a[" << i << "] = " << a[i] << "\n";
}
Works with: C++11

Similar to above but using initialization schematics.

#include <vector>                                                                                                       
#include <iostream>
 
int main() {
std::vector<int> a {1, 2, 3, 4};
std::vector<int> b {5, 6, 7, 8, 9};
 
a.insert(a.end(), b.begin(), b.end());
 
for(int& i: a) std::cout << i << " ";
std::cout << std::endl;
return 0;
}

[edit] C#

using System;
 
namespace RosettaCode
{
class Program
{
static void Main(string[] args)
{
int[] a = { 1, 2, 3 };
int[] b = { 4, 5, 6 };
 
int[] c = new int[a.Length + b.Length];
a.CopyTo(c, 0);
b.CopyTo(c, a.Length);
 
foreach(int n in c)
{
Console.WriteLine(n.ToString());
}
}
}
}

Alternatively, using LINQ extension methods:

Works with: C# version 3
using System.Linq;
 
class Program
{
static void Main(string[] args)
{
int[] a = { 1, 2, 3 };
int[] b = { 4, 5, 6 };
 
int[] c = a.Concat(b).ToArray();
}
}

[edit] Clojure

(concat [1 2 3] [4 5 6])

The inputs can be any collection, including Java arrays, and returns a lazy sequence of the elements.


[edit] CoffeeScript

 
# like in JavaScript
a = [1, 2, 3]
b = [4, 5, 6]
c = a.concat b
 

[edit] Common Lisp

concatenate is a general function for concatenating any type of sequence. It takes the type of sequence to produce, followed by any number of sequences of any type.

(concatenate 'vector #(0 1 2 3) #(4 5 6 7))
=> #(0 1 2 3 4 5 6 7)

[edit] Component Pascal

BlackBox Component Builder

 
MODULE ArrayConcat;
IMPORT StdLog;
 
PROCEDURE Concat(x: ARRAY OF INTEGER; y: ARRAY OF INTEGER; OUT z: ARRAY OF INTEGER);
VAR
i: INTEGER;
BEGIN
ASSERT(LEN(x) + LEN(y) <= LEN(z));
FOR i := 0 TO LEN(x) - 1 DO z[i] := x[i] END;
FOR i := 0 TO LEN(y) - 1 DO z[i + LEN(x)] := y[i] END
END Concat;
 
PROCEDURE Concat2(x: ARRAY OF INTEGER;y: ARRAY OF INTEGER): POINTER TO ARRAY OF INTEGER;
VAR
z: POINTER TO ARRAY OF INTEGER;
i: INTEGER;
BEGIN
NEW(z,LEN(x) + LEN(y));
FOR i := 0 TO LEN(x) - 1 DO z[i] := x[i] END;
FOR i := 0 TO LEN(y) - 1 DO z[i + LEN(x)] := y[i] END;
RETURN z;
END Concat2;
 
PROCEDURE ShowArray(x: ARRAY OF INTEGER);
VAR
i: INTEGER;
BEGIN
i := 0;
StdLog.Char('[');
WHILE (i < LEN(x)) DO
StdLog.Int(x[i]);IF i < LEN(x) - 1 THEN StdLog.Char(',') END;
INC(i)
END;
StdLog.Char(']');StdLog.Ln;
END ShowArray;
 
PROCEDURE Do*;
VAR
x: ARRAY 10 OF INTEGER;
y: ARRAY 15 OF INTEGER;
z: ARRAY 25 OF INTEGER;
w: POINTER TO ARRAY OF INTEGER;
i: INTEGER;
BEGIN
FOR i := 0 TO LEN(x) - 1 DO x[i] := i END;
FOR i := 0 TO LEN(y) - 1 DO y[i] := i END;
Concat(x,y,z);StdLog.String("1> ");ShowArray(z);
 
NEW(w,LEN(x) + LEN(y));
Concat(x,y,z);StdLog.String("2:> ");ShowArray(z);
 
StdLog.String("3:> ");ShowArray(Concat2(x,y));
END Do;
 
END ArrayConcat.
 

Execute: ^Q ArrayConcat.Do
Output:

1> [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
2:> [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
3:> [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]

[edit] D

import std.stdio: writeln;
 
void main() {
int[] a = [1, 2];
int[] b = [4, 5, 6];
 
writeln(a, " ~ ", b, " = ", a ~ b);
}

Output:

[1, 2] ~ [4, 5, 6] = [1, 2, 4, 5, 6]

[edit] Delphi

type
TReturnArray = array of integer; //you need to define a type to be able to return it
 
function ConcatArray(a1,a2:array of integer):TReturnArray;
var
i,r:integer;
begin
{ Low(array) is not necessarily 0 }
SetLength(result,High(a1)-Low(a1)+High(a2)-Low(a2)+2); //BAD idea to set a length you won't release, just to show the idea!
r:=0; //index on the result may be different to indexes on the sources
for i := Low(a1) to High(a1) do begin
result[r] := a1[i];
Inc(r);
end;
for i := Low(a2) to High(a2) do begin
result[r] := a2[i];
Inc(r);
end;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
var
a1,a2:array of integer;
r1:array of integer;
i:integer;
begin
SetLength(a1,4);
SetLength(a2,3);
for i := Low(a1) to High(a1) do
a1[i] := i;
for i := Low(a2) to High(a2) do
a2[i] := i;
TReturnArray(r1) := ConcatArray(a1,a2);
for i := Low(r1) to High(r1) do
showMessage(IntToStr(r1[i]));
Finalize(r1); //IMPORTANT!
ShowMessage(IntToStr(High(r1)));
end;

[edit] E

? [1,2] + [3,4]
# value: [1, 2, 3, 4]


[edit] ECL

 
A := [1, 2, 3, 4];
B := [5, 6, 7, 8];
 
C := A + B;

[edit] Efene

using the ++ operator and the lists.append function

 
@public
run = fn () {
A = [1, 2, 3, 4]
B = [5, 6, 7, 8]
 
C = A ++ B
D = lists.append([A, B])
 
io.format("~p~n", [C])
io.format("~p~n", [D])
}

[edit] EGL

Works with: EDT
 
program ArrayConcatenation
function main()
a int[] = [ 1, 2, 3 ];
b int[] = [ 4, 5, 6 ];
c int[];
c.appendAll(a);
c.appendAll(b);
 
for (i int from 1 to c.getSize())
SysLib.writeStdout("Element " :: i :: " = " :: c[i]);
end
end
end
 

[edit] Elena

#define extensions.
 
#symbol program =
[
#var a := (1,2,3).
#var b := (4,5).
 
consoleEx writeLine:"(":a:") + (":b:") = (":(a + b):")".
].

[edit] Emacs Lisp

See Scheme

[edit] Erlang

In erlang, you can use the ++ operator or lists:append, which is implemented via ++.

On the shell,

 
1> [1, 2, 3] ++ [4, 5, 6].
[1,2,3,4,5,6]
2> lists:append([1, 2, 3], [4, 5, 6]).
[1,2,3,4,5,6]
3>
 

[edit] Euphoria

sequence s1,s2,s3
s1 = {1,2,3}
s2 = {4,5,6}
s3 = s1 & s2
? s3

Output:

{1,2,3,4,5,6}

[edit] F#

Array concatenation.

let a = [|1; 2; 3|]
let b = [|4; 5; 6;|]
let c = Array.append a b

List concatenation (@ and List.append are equivalent).

let x = [1; 2; 3]
let y = [4; 5; 6]
let z1 = x @ y
let z2 = List.append x y

[edit] FBSL

Array concatenation:

#APPTYPE CONSOLE
 
DIM aint[] ={1, 2, 3}, astr[] ={"one", "two", "three"}, asng[] ={!1, !2, !3}
 
FOREACH DIM e IN ARRAYMERGE(aint, astr, asng)
PRINT e, " ";
NEXT
 
PAUSE

Output:

1 2 3 one two three 1.000000 2.000000 3.000000
Press any key to continue...

[edit] Factor

append

Example:

( scratchpad ) USE: sequences
( scratchpad ) { 1 2 } { 3 4 } append .
{ 1 2 3 4 }

[edit] Fantom

In fansh:

 
> a := [1,2,3]
> b := [4,5,6]
> a.addAll(b)
> a
[1,2,3,4,5,6]
 

Note 'addAll' is destructive. Write 'a.dup.addAll(b)' to create a fresh list.

[edit] Forth

: $!+   ( a u a' -- a'+u )  
2dup + >r swap move r> ;
: cat ( a2 u2 a1 u1 -- a3 u1+u2 )
align here dup >r $!+ $!+ r> tuck - dup allot ;
 
\ TEST
create a1 1 , 2 , 3 ,
create a2 4 , 5 ,
a2 2 cells a1 3 cells cat dump
 
8018425F0: 01 00 00 00 00 00 00 00 - 02 00 00 00 00 00 00 00 ................
801842600: 03 00 00 00 00 00 00 00 - 04 00 00 00 00 00 00 00 ................
801842610: 05 00 00 00 00 00 00 00 - ........
 

[edit] Fortran

Works with: Fortran version 90 and later
program Concat_Arrays
implicit none
 
integer, dimension(3) :: a = [ 1, 2, 3 ]
integer, dimension(3) :: b = [ 4, 5, 6 ]
integer, dimension(:), allocatable :: c
 
allocate(c(size(a)+size(b)))
c(1:size(a)) = a
c(size(a)+1:size(a)+size(b)) = b
 
write(*,*) c
 
end program Concat_Arrays
Works with: Fortran version 2003 and later
program Concat_Arrays
implicit none
 
integer, dimension(3) :: a = [ 1, 2, 3 ]
integer, dimension(3) :: b = [ 4, 5, 6 ]
integer, dimension(:), allocatable :: c
 
c = [a, b]
 
write(*,*) c
 
end program Concat_Arrays

[edit] Frink

 
a = [1,2]
b = [3,4]
a.pushAll[b]
 

[edit] FunL

arr1 = array( [1, 2, 3] )
arr2 = array( [4, 5, 6] )
arr3 = array( [7, 8, 9] )
 
println( arr1 + arr2 + arr3 )
Output:
ArraySeq(1, 2, 3, 4, 5, 6, 7, 8, 9)

[edit] GAP

# Concatenate arrays
Concatenation([1, 2, 3], [4, 5, 6], [7, 8, 9]);
# [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
 
# Append to a variable
a := [1, 2, 3];
Append(a, [4, 5, 6);
Append(a, [7, 8, 9]);
a;
# [ 1, 2, 3, 4, 5, 6, 7, 8, 9 ]

[edit] Go

package main
 
import "fmt"
 
func main() {
// Example 1: Idiomatic in Go is use of the append function.
// Elements must be of identical type.
a := []int{1, 2, 3}
b := []int{7, 12, 60} // these are technically slices, not arrays
c := append(a, b...)
fmt.Println(c)
 
// Example 2: Polymorphism.
// interface{} is a type too, one that can reference values of any type.
// This allows a sort of polymorphic list.
i := []interface{}{1, 2, 3}
j := []interface{}{"Crosby", "Stills", "Nash", "Young"}
k := append(i, j...) // append will allocate as needed
fmt.Println(k)
 
// Example 3: Arrays, not slices.
// A word like "array" on RC often means "whatever array means in your
// language." In Go, the common role of "array" is usually filled by
// Go slices, as in examples 1 and 2. If by "array" you really mean
// "Go array," then you have to do a little extra work. The best
// technique is almost always to create slices on the arrays and then
// use the copy function.
l := [...]int{1, 2, 3}
m := [...]int{7, 12, 60} // arrays have constant size set at compile time
var n [len(l) + len(m)]int
copy(n[:], l[:]) // [:] creates a slice that references the entire array
copy(n[len(l):], m[:])
fmt.Println(n)
 
}

Output:

[1 2 3 7 12 60]
[1 2 3 Crosby Stills Nash Young]
[1 2 3 7 12 60]

Array concatenation needs can vary. Here is another set of examples that illustrate different techniques.

package main
 
import (
"reflect"
"fmt"
)
 
// Generic version
// Easier to make the generic version accept any number of arguments,
// and loop trough them. Otherwise there will be lots of code duplication.
func ArrayConcat(arrays ...interface{}) interface{} {
if len(arrays) == 0 {
panic("Need at least one arguemnt")
}
var vals = make([]*reflect.SliceValue, len(arrays))
var arrtype *reflect.SliceType
var totalsize int
for i,a := range arrays {
v := reflect.NewValue(a)
switch t := v.Type().(type) {
case *reflect.SliceType:
if arrtype == nil {
arrtype = t
} else if t != arrtype {
panic("Unequal types")
}
vals[i] = v.(*reflect.SliceValue)
totalsize += vals[i].Len()
default: panic("not a slice")
}
}
ret := reflect.MakeSlice(arrtype,totalsize,totalsize)
targ := ret
for _,v := range vals {
reflect.Copy(targ, v)
targ = targ.Slice(v.Len(),targ.Len())
}
return ret.Interface()
}
 
// Type specific version
func ArrayConcatInts(a, b []int) []int {
ret := make([]int, len(a) + len(b))
copy(ret, a)
copy(ret[len(a):], b)
return ret
}
 
func main() {
test1_a, test1_b := []int{1,2,3}, []int{4,5,6}
test1_c := ArrayConcatInts(test1_a, test1_b)
fmt.Println(test1_a, " + ", test1_b, " = ", test1_c)
 
test2_a, test2_b := []string{"a","b","c"}, []string{"d","e","f"}
test2_c := ArrayConcat(test2_a, test2_b).([]string)
fmt.Println(test2_a, " + ", test2_b, " = ", test2_c)
}

Output:

[1 2 3]  +  [4 5 6]  =  [1 2 3 4 5 6]
[a b c]  +  [d e f]  =  [a b c d e f]

[edit] Gosu

 
var listA = { 1, 2, 3 }
var listB = { 4, 5, 6 }
 
var listC = listA.concat( listB )
 
print( listC ) // prints [1, 2, 3, 4, 5, 6]
 

[edit] Groovy

Solution:

def list = [1, 2, 3] + ["Crosby", "Stills", "Nash", "Young"]

Test:

println list

Output:

[1, 2, 3, Crosby, Stills, Nash, Young]

[edit] Haskell

A list is in Haskell one of the most common composite data types (constructed from other types). In the documentation we read for the append operation ++:

(++) :: [a] -> [a] -> [a]
Append two lists, i.e.:
 
[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
[x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]

If the first list is not finite, the result is the first list.

[edit] HicEst

REAL :: a(7), b(3), c(10)
 
c = a
DO i = 1, LEN(b)
c(i + LEN(a)) = b(i)
ENDDO

[edit] Icon and Unicon

Both languages have list concatenation built in. Lists are fully dynamic arrays which can be truncated or extended at either end.

 
procedure main()
L1 := [1, 2, 3, 4]
L2 := [11, 12, 13, 14]
L3 := L1 ||| L2
 
sep := ""
every writes(sep, !L3) do
sep := ", "
write()
end
 

[edit] IDL

Array concatenation can mean different things, depending on the number of dimensions of the arguments and the result. In the simplest case, with 1-dimensional arrays to begin with, there are two obvious ways to concatenate them. If my arrays are these:

 
> a = [1,2,3]
> b = [4,5,6]
> help,a
A INT = Array[3]
> help,b
B INT = Array[3]
> print,a
1 2 3
> print,b
4 5 6
 

Then they can be concatenated "at the ends":

 
> help,[a,b]
<Expression> INT = Array[6]
> print,[a,b]
1 2 3 4 5 6
 

or "at the sides":

 
> help,[[a],[b]]
<Expression> INT = Array[3, 2]
> print,[[a],[b]]
1 2 3
4 5 6
 

Note that this requires that the arrays have the same size at the side at which they are concatenated:

 
> b = transpose(b)
> help,b
B INT = Array[1, 3]
> print,b
4
5
6
> print,[a,b]
Unable to concatenate variables because the dimensions do not agree: B.
Execution halted at: $MAIN$
> print,[[a],[b]]
Unable to concatenate variables because the dimensions do not agree: B.
Execution halted at: $MAIN$
 

This can get a lot more complicated as a 3x4x5-element three-dimensional array can be concatenated with a 5x2x3-element array at exactly two "surfaces".

[edit] Inform 7

let A be {1, 2, 3};
let B be {4, 5, 6};
add B to A;

[edit] Ioke

iik> [1,2,3] + [3,2,1]
[1,2,3] + [3,2,1]
+> [1, 2, 3, 3, 2, 1]

[edit] J

Solution: ,

Example:

   array1 =: 1 2 3
array2 =: 4 5 6
array1 , array2
1 2 3 4 5 6

Of course, in J, array concatenation works (consistently) on arrays of any rank or dimension.

The verb , concatenates by treating the argument array with the largest number of dimensions as a list. Other primary verbs concatenate along other axes.

   ]ab=: 3 3 $ 'aaabbbccc'
aaa
bbb
ccc
]wx=: 3 3 $ 'wxyz'
wxy
zwx
yzw
ab , wx
aaa
bbb
ccc
wxy
zwx
yzw
ab ,. wx
aaawxy
bbbzwx
cccyzw
ab ,: wx
aaa
bbb
ccc
 
wxy
zwx
yzw
$ ab , wx NB. applies to first (highest) axis
6 3
$ ab ,. wx NB. applies to last (atomic) axis
3 6
$ ab ,: wx NB. applies to new (higher) axis
2 3 3

[edit] Java

From [1]:

public static Object[] objArrayConcat(Object[] o1, Object[] o2)
{
Object[] ret = new Object[o1.length + o2.length];
 
System.arraycopy(o1, 0, ret, 0, o1.length);
System.arraycopy(o2, 0, ret, o1.length, o2.length);
 
return ret;
}

Or with Collections simply call addAll:

Collection list1, list2, list1And2;
//...list1 and list2 are instantiated...
list1And2 = new ArrayList(list1); //or any other Collection you want
list1And2.addAll(list2);

[edit] JavaScript

The Array.concat() method returns a new array comprised of this array joined with other array(s) and/or value(s).

var
a = [1,2,3],
b = [4,5,6],
c = a.concat(b); // [1,2,3,4,5,6]

[edit] jq

If a and b are two arrays, then a+b is their concatenation. Similarly for a+b+c. To concatenate the component arrays of an array, A, the flatten filter is available in recent versions of jq. If your jq does not have flatten, then the task can be accomplished by:

   reduce A[] as $a ([]. + $a)
jq also supports streams, which are somewhat array-like, so it may be worth mentioning that the concatenation of two or more streams can be accomplished using "," instead of "+".
[1,2] + [3] + [null] # => [1,2,3,null]
 
[range(1;3), 3, null] # => [1,2,3,null]
 

[edit] Julia

a = [1,2,3]
b = [4,5,6]
ab = [a,b]
# the above bracket notation simply generates a call to vcat
ab = vcat(a,b)
# hcat is short for `horizontal concatenation`
ab = hcat(a,b) #ab -> 3x2 matrix
# the append!(a,b) method is mutating, appending `b` to `a`
append!(a,b) # a now equals [1,2,3,4,5,6]

[edit] K

 
a: 1 2 3
b: 4 5 6
a,b
1 2 3 4 5 6

Concatenations on larger dimensions also use ",", often combined with other operations.

 
ab:3 3#"abcdefghi"
("abc"
"def"
"ghi")
 
dd:3 3#"012345678"
("012"
"345"
"678")
 
ab,dd
("abc"
"def"
"ghi"
"012"
"345"
"678")
 
+ab,dd / flip (transpose) join
("adg036"
"beh147"
"cfi258")
 
ab,'dd / eachpair join
("abc012"
"def345"
"ghi678")
 
+(+ab),dd
("abc036"
"def147"
"ghi258")

[edit] Kotlin

There is no operator or standard library function for concatenating Array types. One option is to convert to Collections, concatenate, and convert back:

val a : Array<T> = // initialise a
val b : Array<T> = // initialise b
val c = (a.toList() + b.toList()).copyToArray()

Alternatively, we can write our own concatenation function:

fun arrayConcat(a : Array<Any>, b : Array<Any>)
= Array<Any>(a.size + b.size, {if (it in a.indices) a[it] else b[it - a.size]})

When working directly with Collections, we can simply use the + operator:

val a : Collection<T> // initialise a
val b : Collection<T> = // initialise b
val c : Collection = a + b

[edit] LabVIEW

Use the Build Array function.
This image is a VI Snippet, an executable image of LabVIEW code. The LabVIEW version is shown on the top-right hand corner. You can download it, then drag-and-drop it onto the LabVIEW block diagram from a file browser, and it will appear as runnable, editable code.
LabVIEW Array concatenation.png

[edit] Lang5

[1 2] [3 4] append collapse .

[edit] LFE

 
> (++ '(1 2 3) '(4 5 6))
(1 2 3 4 5 6)
> (: lists append '(1 2 3) '(4 5 6))
(1 2 3 4 5 6)
 

[edit] Liberty BASIC

    x=10
y=20
dim array1(x)
dim array2(y)
 
[concatenate]
dim array3(x + y)
for i = 1 to x
array3(i) = array1(i)
next
for i = 1 to y
array3(i + x) = array2(i)
next
 
[print]
for i = 1 to x + y
print array3(i)
next


[edit] Lasso

 
local(arr1 = array(1, 2, 3))
local(arr2 = array(4, 5, 6))
local(arr3 = #arr1->asCopy) // make arr3 a copy of arr2
#arr3->merge(#arr2) // concatenate 2 arrays
 
 
Result:
 
arr1 = array(1, 2, 3)
arr2 = array(4, 5, 6)
arr3 = array(4, 5, 6)
arr3 = array(1, 2, 3, 4, 5, 6)

[edit]

COMBINE is used to combine lists or words. SENTENCE is used to combine lists and words into a single list.

 
to combine-arrays :a1 :a2
output listtoarray sentence arraytolist :a1 arraytolist :a2
end
show combine-arrays {1 2 3} {4 5 6}  ; {1 2 3 4 5 6}
 

[edit] Lua

a = {1,2,3}
b = {4,5,6}
table.foreach(b,function(i,v)table.insert(a,v)end)
for i,v in next,a do io.write (v..' ') end

[edit] Maple

There is a built-in procedure for concatenating arrays (and similar objects such as matrices or vectors). Arrays can be concatenated along any given dimension, which is specified as the first argument.

 
> A := Array( [ 1, 2, 3 ] );
A := [1, 2, 3]
 
> B := Vector['row']( [ sin( x ), cos( x ), tan( x ) ] );
B := [sin(x), cos(x), tan(x)]
 
> ArrayTools:-Concatenate( 1, A, B ); # stack vertically
[ 1 2 3 ]
[ ]
[sin(x) cos(x) tan(x)]
 
> ArrayTools:-Concatenate( 2, A, B ); # stack horizontally
[1, 2, 3, sin(x), cos(x), tan(x)]
 
> M := << a, b, c ; d, e, f >>; # a matrix
[a b c]
M := [ ]
[d e f]
 
> ArrayTools:-Concatenate( 1, M, A );
[a b c]
[ ]
[d e f]
[ ]
[1 2 3]
 

Of course, the order of the arguments is important.

 
> ArrayTools:-Concatenate( 1, A, M );
[1 2 3]
[ ]
[a b c]
[ ]
[d e f]
 

Lists, in Maple, might be considered to be a kind of "array" (in the sense that they look like arrays in memory), though they are actually immutable objects. However, they can be concatenated as follows.

 
> L1 := [ 1, 2, 3 ];
L1 := [1, 2, 3]
 
> L2 := [ a, b, c ];
L2 := [a, b, c]
 
> [ op( L1 ), op( L2 ) ];
[1, 2, 3, a, b, c]
 
> [ L1[], L2[] ]; # equivalent, just different syntax
[1, 2, 3, a, b, c]
 

[edit] Mathematica

Join[{1,2,3}, {4,5,6}]
 
-> {1, 2, 3, 4, 5, 6}

[edit] MATLAB / Octave

Two arrays are concatenated by placing the two arrays between a pair of square brackets. A space between the two array names will concatenate them horizontally, and a semi-colon between array names will concatenate vertically.

>> a = [1 2 3]
 
a =
 
1 2 3
 
>> b = [4 5 6]
 
b =
 
4 5 6
 
>> concat = [a b]
 
concat =
 
1 2 3 4 5 6
 
>> concat = [a;b]
 
concat =
 
1 2 3
4 5 6

For multi-dimensional arrays, there is also the function cat():

>> c = randn([3,4,5]);
>> d = randn([3,4,7]);
>> e = cat(3,c,d);
>> size(e)
ans =
 
3 4 12
 
 

[edit] Maxima

u: [1, 2, 3, 4]$
v: [5, 6, 7, 8, 9, 10]$
append(u, v);
/* [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] */
 
/* There are also functions for matrices */
 
a: matrix([6, 1, 8],
[7, 5, 3],
[2, 9, 4])$
 
addcol(a, ident(3));
/* matrix([6, 1, 8, 1, 0, 0],
[7, 5, 3, 0, 1, 0],
[2, 9, 4, 0, 0, 1]) */
 
addrow(a, ident(3));
/* matrix([6, 1, 8],
[7, 5, 3],
[2, 9, 4],
[1, 0, 0],
[0, 1, 0],
[0, 0, 1]) */

[edit] Mercury

A `append` B = C

It could be "as simple as array1 + array2", but the 'array' module names the operation 'append' rather than '+'. It's tempting to just say that Mercury supports ad-hoc polymorphism - it can infer that a bare '+' refers to 'float.+' or 'int.+' (or that the 'append' above is array.append, rather than list.append), by the types involved - but it also handles other ambiguities in the same way. For instance, Mercury (like Prolog and Erlang) treats the arity of a function as part of its name, where a(1, 2) and a(1) involve the distinct functions a/2 and a/1. But Mercury also (unlike Prolog and Erlang) supports currying, where a(1) is a function that accepts a/2's second argument. So, is [a(X), a(Y), a(Z)] a list of whatever type a/1 evaluates to, or is it a list of curried a/2?

[edit] Nemerle

using System.Console;
using Nemerle.Collections;
 
module ArrayCat
{
Main() : void
{
def arr1 = array[1, 2, 3]; def arr2 = array[4, 5, 6];
def arr12 = arr1.Append(arr2); // <----
foreach (i in arr12) Write($"$i ");
}
}

[edit] NetRexx

NetRexx arrays are identical to Java's so all the techniques described in the Java section apply to NetRexx too. This example uses the Collection classes to merge two arrays.

/* NetRexx */
options replace format comments java crossref savelog symbols nobinary
 
cymru = [ 'Ogof Ffynnon Ddu', 'Ogof Draenen' ]
 
dlm = '-'.copies(40)
 
say dlm
loop c_ = 0 to cymru.length - 1
say c_ cymru[c_]
end c_
 
yorks = [ 'Malham Tarn Pot', 'Greygill Hole' ]
 
say dlm
loop y_ = 0 to yorks.length - 1
say y_ yorks[y_]
end y_
 
merge = ArrayList()
merge.addAll(Arrays.asList(cymru))
merge.addAll(Arrays.asList(yorks))
 
say dlm
merged = merge.toArray()
loop m_ = 0 to merged.length - 1
say m_ merged[m_]
end m_
 

Output:

---------------------------------------- 
0 Ogof Ffynnon Ddu 
1 Ogof Draenen 
---------------------------------------- 
0 Malham Tarn Pot 
1 Greygill Hole 
---------------------------------------- 
0 Ogof Ffynnon Ddu 
1 Ogof Draenen 
2 Malham Tarn Pot 
3 Greygill Hole 

[edit] NewLISP

; file:   arraycon.lsp
; url: http://rosettacode.org/wiki/Array_concatenation
; author: oofoe 2012-01-28
 
(println "Append lists: " (append '(3 a 5 3) (sequence 1 9)))
 
(println "Multi append: "
(append '(this is)
'(a test)
'(of the emergency)
(sequence 3 1)))
 
(println "Append arrays: "
(append '((x 56) (b 99)) '((z 34) (c 23) (r 88))))
 
(exit)

Sample output:

Append lists:  (3 a 5 3 1 2 3 4 5 6 7 8 9)
Multi append:  (this is a test of the emergency 3 2 1)
Append arrays: ((x 56) (b 99) (z 34) (c 23) (r 88))

[edit] Nimrod

Dynamic sized Sequences can simply be concatenated:

var
x = @[1,2,3,4,5,6]
y = @[7,8,9,10,11]
z = x & y

Static sized Arrays:

var
a = [1,2,3,4,5,6]
b = [7,8,9,10,11]
c: array[11, int]
 
c[0..5] = a
c[6..10] = b

[edit] Objeck

 
bundle Default {
class Arithmetic {
function : Main(args : String[]) ~ Nil {
array1 := [3, 5, 7];
array2 := [2, 4, 6];
 
array3 := Copy(array1, array2);
each(i : array3) {
array3[i]->PrintLine();
};
}
 
function : native : Copy(array1 : Int[], array2 : Int[]) ~ Int[] {
max := array1->Size() + array2->Size();
array3 := Int->New[max];
 
i := 0;
for(i := i; i < array1->Size(); i += 1;) {
array3[i] := array1[i];
};
 
j := 0;
for(i := i; i < max; i += 1;) {
array3[i] := array2[j];
j += 1;
};
 
return array3;
}
}
}
 

[edit] Objective-C

with immutable arrays:

NSArray *arr1 = @[@1, @2, @3];
NSArray *arr2 = @[@4, @5, @6];
NSArray *arr3 = [arr1 arrayByAddingObjectsFromArray:arr2];

or adding onto a mutable array:

NSArray *arr1 = @[@1, @2, @3];
NSArray *arr2 = @[@4, @5, @6];
NSMutableArray *arr3 = [NSMutableArray arrayWithArray:arr1];
[arr3 addObjectsFromArray:arr2];

[edit] OCaml

It is more natural in OCaml to use lists instead of arrays:

# let list1 = [1; 2; 3];;
val list1 : int list = [1; 2; 3]
# let list2 = [4; 5; 6];;
val list2 : int list = [4; 5; 6]
# let list1and2 = list1 @ list2;;
val list1and2 : int list = [1; 2; 3; 4; 5; 6]

If you want to use arrays:

# let array1 = [|1; 2; 3|];;
val array1 : int array = [|1; 2; 3|]
# let array2 = [|4; 5; 6|];;
val array2 : int array = [|4; 5; 6|]
# let array1and2 = Array.append array1 array2;;
val array1and2 : int array = [|1; 2; 3; 4; 5; 6|]

[edit] ooRexx

 
a = .array~of(1,2,3)
say "Array a has " a~items "items"
b = .array~of(4,5,6)
say "Array b has " b~items "items"
a~appendall(b) -- adds all items from b to a
say "Array a now has " a~items "

[edit] Order

Order supports two main aggregate types: tuples and sequences (similar to lists in other languages). Most "interesting" operations are limited to sequences, but both support an append operation, and each can be converted to the other.

#include <order/interpreter.h>
 
ORDER_PP( 8tuple_append(8tuple(1, 2, 3), 8tuple(4, 5, 6), 8pair(7, 8)) )
// -> (1,2,3,4,5,6,7,8)
 
ORDER_PP( 8seq_append(8seq(1, 2, 3), 8seq(4, 5, 6), 8seq(7, 8)) )
// -> (1)(2)(3)(4)(5)(6)(7)(8)

[edit] OxygenBasic

 
'CREATE DYNAMIC ARRAY SPACES USING STRINGS
 
string sa=nuls 5* sizeof float
string sb=sa
 
'MAP ARRAY VARIABLES ONTO STRINGS
 
float a at *sa
float b at *sb
 
'ASSIGN SOME VALUES
 
a<=10,20,30,40,50
b<=60,70,80,90,00
 
'ADD ARRAY B TO A BY STRING CONCATENATION
 
sa+=sb
 
'TEST
 
print a[7] 'result 70
 

[edit] Oz

List are concatenated with List.append (shortcut: Append). Tuples are concatened with Tuple.append. Arrays do exist in Oz, but are rarely used.

%% concatenating 2 lists
{Append [a b] [c d]} = [a b c d]
 
%% concatenating 2 tuples
{Tuple.append t(1 2 3) u(4 5 6)} = u(1 2 3 4 5 6)

[edit] PARI/GP

concat(u,v)

[edit] Pascal

See Delphi

[edit] Perl

In Perl, arrays placed into list context are flattened:

my @arr1 = (1, 2, 3);
my @arr2 = (4, 5, 6);
my @arr3 = (@arr1, @arr2);

The push function appends elements onto an existing array:

my @arr1 = (1, 2, 3);
my @arr2 = (4, 5, 6);
push @arr1, @arr2;
print "@arr1\n"; # prints "1 2 3 4 5 6"

[edit] Perl 6

# the comma ',' can be used to concatenate arrays:
sub concatenateArrays(@a, @b) {
@a, @b
}
 
my @a1 = (1,2,3);
my @a2 = (2,3,4);
concatenateArrays(@a1,@a2).join(", ").say;

[edit] PHP

$arr1 = array(1, 2, 3);
$arr2 = array(4, 5, 6);
$arr3 = array_merge($arr1, $arr2);

[edit] PicoLisp

PicoLisp has no built-in array data type. Lists are used instead.

There are destructive concatenations:

: (setq  A (1 2 3)  B '(a b c))
-> (a b c)
: (conc A B) # Concatenate lists in 'A' and 'B'
-> (1 2 3 a b c)
: A
-> (1 2 3 a b c) # Side effect: List in 'A' is modified!

and non-destructive concatenations:

: (setq  A (1 2 3)  B '(a b c))
-> (a b c)
: (append A B) # Append lists in 'A' and 'B'
-> (1 2 3 a b c)
: A
-> (1 2 3)
: B
-> (a b c) # Arguments are not modified

[edit] PL/I

Trivial example requires no computational statement. Note that the arrays are not in static storage:

 
declare x(12) fixed;
declare b(5) fixed defined x;
declare c(7) fixed defined x(1sub+5);
 

A more general example using dynamic bounds. Again, no computation statement is required.

 
declare x(m+n) fixed;
declare b(m) fixed defined x;
declare c(n) fixed defined x(1sub+hbound(b,1));
 

An alternative, that can be used to advantage for matrices as well as vectors, follows. This example illustrates extending a matrix diagonally. Although fixed array bounds are used in the declarations, the bounds can be dynamic. Matrix B is extended by placing matrix C on its diagonal:

 
declare a(5,6) fixed;
declare b(3,4) fixed defined a(1sub, 2sub);
declare c(2,2) fixed defined a(1sub+hbound(b,1), 2sub+hbound(b,2));
declare (i, j, k) fixed;
 
a = 0;
put skip list ('Please type elements for a 3 x 4 matrix:');
get list (b);
put skip list ('Please type elements for a 2 x 2 matrix:');
get list (c);
put skip edit (c) ( skip, (hbound(c,2)) f(5,0) );
 
put skip list ('Composite matrix:');
put skip edit (a) ( skip, (hbound(a,2)) f(5,0) );
 

Output:

 
Please type elements for a 3 x 4 matrix:
 
Please type elements for a 2 x 2 matrix:
 
13 14
15 16
Composite matrix:
 
1 2 3 4 0 0
5 6 7 8 0 0
9 10 11 12 0 0
0 0 0 0 13 14
0 0 0 0 15 16
 
 

[edit] PostScript

Library: initlib
 
[1 2 3 4] [5 6 7 8] concat
 

[edit] PowerShell

$a = 1,2,3
$b = 4,5,6
 
$c = $a + $b
Write-Host $c

[edit] Prolog

 
?- append([1,2,3],[4,5,6],R).
R = [1, 2, 3, 4, 5, 6].
 

[edit] PureBasic

Procedure displayArray(Array a(1), msg.s)
Protected i
Print(msg + " [")
For i = 0 To ArraySize(a())
Print(Str(a(i)))
If i <> ArraySize(a())
Print(", ")
EndIf
Next
PrintN("]")
EndProcedure
 
Procedure randomElements(Array a(1), lo, hi)
Protected i
For i = 0 To ArraySize(a())
a(i) = random(hi - lo) + lo
Next
EndProcedure
 
Procedure arrayConcat(Array a(1), Array b(1), Array c(1))
Protected i, newSize = ArraySize(a()) + ArraySize(b()) + 1
Dim c(newSize)
For i = 0 To ArraySize(a())
c(i) = a(i)
Next
For i = 0 To ArraySize(b())
c(i + ArraySize(a()) + 1) = b(i)
Next
EndProcedure
 
 
If OpenConsole()
Dim a(random(3) + 1)
Dim b(random(3) + 1)
Dim c(0) ;array will be resized by arrayConcat()
 
randomElements(a(), -5, 5)
randomElements(b(), -5, 5)
displayArray(a(), "a:")
displayArray(b(), "b:")
arrayConcat(a(), b(), c())
displayArray(c(), "concat of a[] + b[]:")
 
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
Input()
CloseConsole()
EndIf

Sample output:

a: [5, 2, -4, -1, -2]
b: [0, -4, -1]
concat of a[] + b[]: [5, 2, -4, -1, -2, 0, -4, -1]

[edit] Python

The + operator concatenates two lists and returns a new list. The list.extend method appends elements of another list to the receiver.

arr1 = [1, 2, 3]
arr2 = [4, 5, 6]
arr3 = [7, 8, 9]
arr4 = arr1 + arr2
assert arr4 == [1, 2, 3, 4, 5, 6]
arr4.extend(arr3)
assert arr4 == [1, 2, 3, 4, 5, 6, 7, 8, 9]

Note: list.extend is normally accomplished using the += operator like this:

arr5 = [4, 5, 6]
arr6 = [7, 8, 9]
arr6 += arr5
assert arr6 == [7, 8, 9, 4, 5, 6]

[edit] R

 
a1 <- c(1, 2, 3)
a2 <- c(3, 4, 5)
a3 <- c(a1, a2)
 

[edit] Racket

 
(vector-append #(1 2 3 4) #(5 6 7) #(8 9 10))
 

Output:

'#(1 2 3 4 5 6 7 8 9 10)

[edit] REBOL

 
a1: [1 2 3]
a2: [4 5 6]
a3: [7 8 9]
 
append a1 a2 ; -> [1 2 3 4 5 6]
 
append/only a1 a3 ; -> [1 2 3 4 5 6 [7 8 9]]
 

[edit] Retro

needs array'
 
^array'new{ 1 2 3 } ^array'new{ 4 5 6 } ^array'append

[edit] REXX

REXX doesn't have arrays as such, but it has something that looks, feels, and tastes like arrays: stemmed variables.

Simply, a stemmed array is a variable with an appended dot (.) followed by a constant (such as an integer).
There is no way to preallocate a stemmed variable, REXX just assigns them as they are created (assigned a value).

As such, there isn't an easy way to keep track of the number of "elements" in a REXX "array".
Consider:

a.1 =  10
a.2 = 22.7
a.7 = -12

where now we have three "elements", and they are disjointed (another word for sparse).
There are ways to handle this in REXX however.

When assigning stemmed arrays, it is common to assign "element" zero to the number of values,
assuming that the stemmed variables are sequential.

example:

fact.0=8
fact.1= 1
fact.2= 2
fact.3= 6
fact.4= 24
fact.5= 120
fact.6= 720
fact.7= 5040
fact.8=40320

To concat two "arrays" in REXX, the following assumes that the stemmed variables are in order, with no gaps, and none have a "null" value.

/*REXX program to demonstrates how to perform array concatenation.*/
 
p.= /*(below) a short list of primes.*/
p.1=2; p.2=3; p.3=5; p.4=7; p.5=11; p.6=13
p.7=17; p.8=19; p.9=23; p.10=27; p.11=31; p.12=37
 
f.= /*(below) a list of Fibonacci #s.*/
f.0=0;f.1=1;f.2=1;f.3=2;f.4=3;f.5=5;f.6=8;f.7=13;f.8=21;f.9=34;f.10=55
 
do j=1 while p.j\==''
c.j=p.j /*assign C array with some primes*/
end /*j*/
n=j-1
do k=0 while f.k\==''; n=n+1
c.n=f.k /*assign C array with fib numbers*/
end /*k*/
say 'elements=' n
say
do m=1 for n
say 'c.'m"="c.m /*show a "merged" C array nums.*/
end /*m*/
/*stick a fork in it, we're done.*/

output

elements= 23

c.1=2
c.2=3
c.3=5
c.4=7
c.5=11
c.6=13
c.7=17
c.8=19
c.9=23
c.10=27
c.11=31
c.12=37
c.13=0
c.14=1
c.15=1
c.16=2
c.17=3
c.18=5
c.19=8
c.20=13
c.21=21
c.22=34
c.23=55

[edit] RLaB

In RLaB the matrices can be appended (column-wise) or stacked (row-wise). Consider few examples:

 
>> x = [1, 2, 3]
>> y = [4, 5, 6]
// appending matrix 'y' on the right from matrix 'x' is possible if the two matrices have
// the same number of rows:
>> z1 = [x, y]
matrix columns 1 thru 6
1 2 3 4 5 6
// stacking matrix 'y' below the matrix 'x' is possible if the two matrices have
// the same number of columns:
>> z2 = [x; y]
1 2 3
4 5 6
>>
 

[edit] Ruby

The Array#+ method concatenates two arrays and returns a new array. The Array#concat method appends elements of another array to the receiver.

arr1 = [1, 2, 3]
arr2 = [4, 5, 6]
arr3 = [7, 8, 9]
arr4 = arr1 + arr2 # => [1, 2, 3, 4, 5, 6]
arr4.concat(arr3) # => [1, 2, 3, 4, 5, 6, 7, 8, 9]

[edit] Scala

val arr1 = Array( 1, 2, 3 )
val arr2 = Array( 4, 5, 6 )
val arr3 = Array( 7, 8, 9 )
 
arr1 ++ arr2 ++ arr3
//or:
Array concat ( arr1, arr2, arr3 )
// res0: Array[Int] = Array(1, 2, 3, 4, 5, 6, 7, 8, 9)

[edit] Scheme

; in r5rs, there is append for lists, but we'll need to define vector-append
(define (vector-append . arg) (list->vector (apply append (map vector->list arg))))
 
(vector-append #(1 2 3 4) #(5 6 7) #(8 9 10))
; #(1 2 3 4 5 6 7 8 9 10)

Note : vector-append is also defined in SRFI-43.

[edit] Seed7

$ include "seed7_05.s7i";
 
var array integer: a is [] (1, 2, 3, 4);
var array integer: b is [] (5, 6, 7, 8);
var array integer: c is [] (9, 10);
 
const proc: main is func
local
var integer: number is 0;
begin
c := a & b;
for number range c do
write(number <& " ");
end for;
writeln;
end func;

Output:

1 2 3 4 5 6 7 8

[edit] Sidef

var arr1 = [1, 2, 3];
var arr2 = [4, 5, 6];
var arr3 = (arr1 + arr2); # => [1, 2, 3, 4, 5, 6]

[edit] Slate

The binary operation of concatenation is made with the ; (semi-colon) from the type Sequence. It is also available for appending Sequences to WriteStreams.

 
{1. 2. 3. 4. 5} ; {6. 7. 8. 9. 10}
 

[edit] Smalltalk

Concatenation (appending) is made with the method , (comma), present in classes SequenceableCollection, ArrayedCollection and their subclasses (e.g. Array, String, OrderedCollection ...)

|a b c|
a := #(1 2 3 4 5).
b := #(6 7 8 9 10).
c := a,b.
c displayNl.

[edit] SNOBOL4

Works with: Macro Spitbol
Works with: Snobol4+
Works with: CSnobol
*       # Concatenate 2 arrays (vectors)
define('cat(a1,a2)i,j') :(cat_end)
cat cat = array(prototype(a1) + prototype(a2))
cat1 i = i + 1; cat<i> = a1<i> :s(cat1)
cat2 j = j + 1; cat<i - 1 + j> = a2<j> :s(cat2)f(return)
cat_end
 
* # Fill arrays
str1 = '1 2 3 4 5'; arr1 = array(5)
loop i = i + 1; str1 len(p) span('0123456789') . arr1<i> @p :s(loop)
str2 = '6 7 8 9 10'; arr2 = array(5)
loop2 j = j + 1; str2 len(q) span('0123456789') . arr2<j> @q :s(loop2)
 
* # Test and display
arr3 = cat(arr1,arr2)
loop3 k = k + 1; str3 = str3 arr3<k> ' ' :s(loop3)
output = str1
output = str2
output = str3
end

Output:

1 2 3 4 5
6 7 8 9 10
1 2 3 4 5 6 7 8 9 10

[edit] Standard ML

 
val l1 = [1,2,3,4];;
val l2 = [5,6,7,8];;
val l3 = l1 @ l2 (* [1,2,3,4,5,6,7,8] *)
 

[edit] Swift

let array1 = [1,2,3]
let array2 = [4,5,6]
let array3 = array1 + array2

[edit] Tcl

set a {1 2 3}
set b {4 5 6}
set ab [concat $a $b]; # 1 2 3 4 5 6

Note that in the Tcl language, “arrays” are hash maps of strings to variables, so the notion of concatenation doesn't really apply. What other languages (usually) call arrays are “lists” in Tcl.

[edit] TI-89 BASIC

If a and b are lists, augment(a, b) concatenates them in the usual fashion. If a and b are matrices, then augment(a, b) produces a matrix whose columns are the columns of a followed by the columns of b, i.e. an augmented matrix.

■ augment({1,2}, {3,4})
    {1,2,3,4}
■ augment([[1][2]], [[3][4]])
    [[1,3][2,4]]

That last example as displayed in pretty-printing mode:

\operatorname{augment} \left(\begin{bmatrix}1 \\ 2\end{bmatrix}, \begin{bmatrix}3 \\ 4\end{bmatrix}\right)

\begin{bmatrix}
1 & 3 \\ 
2 & 4
\end{bmatrix}

Concatenation in the other direction may of course be done by transposition:

■ augment([[x][y]], [[z][w]])
    [[x][y][z][w]]

\left(\operatorname{augment} \left(\begin{bmatrix}x \\ y\end{bmatrix}^\mathrm T, \begin{bmatrix}z \\ w\end{bmatrix}^\mathrm T\right)\right)^\mathrm T

\begin{bmatrix} x \\ y \\ z \\ w\end{bmatrix}

[edit] Trith

[1 2 3] [4 5 6] concat

[edit] UNIX Shell

Using proper built-in Bash arrays:

Works with: bash
array1=( 1 2 3 4 5 )
array2=( 6 7 8 9 10 )
botharrays=( ${array1[@]} ${array2[@]} )

Whitespace-delimited strings work in much the same way:

Works with: bash
array1='1 2 3 4 5'
array2='6 7 8 9 10'
 
# Concatenated to a Bash array ...
botharrays_a=( $array1 $array2 )
 
# Concatenated to a string ...
botharrays_s="$array1 $array2"

[edit] Vala

int[] array_concat(int[]a,int[]b){	
int[] c = new int[a.length + b.length];
Memory.copy(c, a, a.length * sizeof(int));
Memory.copy(&c[a.length], b, b.length * sizeof(int));
return c;
}
void main(){
int[] a = {1,2,3,4,5};
int[] b = {6,7,8};
int[] c = array_concat(a,b);
foreach(int i in c){
stdout.printf("%d\n",i);
}
}

[edit] VBScript

Function ArrayConcat(arr1, arr2)
ReDim ret(UBound(arr1) + UBound(arr2) + 1)
For i = 0 To UBound(arr1)
ret(i) = arr1(i)
Next
offset = Ubound(arr1) + 1
For i = 0 To UBound(arr2)
ret(i + offset) = arr2(i)
Next
ArrayConcat = ret
End Function
 
arr1 = array(10,20,30)
arr2 = array(40,50,60)
WScript.Echo "arr1 = array(" & Join(arr1,", ") & ")"
WScript.Echo "arr2 = array(" & Join(arr2,", ") & ")"
arr3 = ArrayConcat(arr1, arr2)
WScript.Echo "arr1 + arr2 = array(" & Join(arr3,", ") & ")"

Output:

arr1 = array(10, 20, 30)
arr2 = array(40, 50, 60)
arr1 + arr2 = array(10, 20, 30, 40, 50, 60)

[edit] Visual Basic .NET

 
Dim iArray1() As Integer = {1, 2, 3}
Dim iArray2() As Integer = {4, 5, 6}
Dim iArray3() As Integer = Nothing
 
iArray3 = iArray1.Concat(iArray2).ToArray
 

[edit] Wart

Wart doesn't have arrays yet, just lists.

a <- '(1 2 3)
b <- '(4 5 6)
a+b
# => (1 2 3 4 5 6)

[edit] Yorick

a = [1,2,3];
b = [4,5,6];
ab = grow(a, b);

[edit] zkl

Lists, no built in support for vectors/arrays/matrices

T(1,2).extend(T(4,5,6)) //-->L(1,2,4,5,6)

[edit] Zsh

Concatenating arrays.

a=(1 2 3)
b=(a b c)
 
c=($a $b)

Pushing a single element into an array.

a+=4

Pushing another array into an array.

a+=($b)
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