Concatenation

Concatenating two arrays together in computer programming involves combining the elements of both arrays into a single array. This operation is commonly performed using methods like concat() in JavaScript or functions like numpy.concatenate() in Python. Concatenation is useful when you need to merge the contents of two arrays to create a larger array, enabling developers to efficiently combine data from different sources or perform operations on larger datasets. It allows for flexible data manipulation, such as joining arrays containing different types of data, merging data from multiple sources, or appending new elements to an existing array.

Select Languages

Examples

C

// No Native Support or Implementation

C#

List<string> carsListKr =
  new List <string>();

carsListKr.Add("Kia");
carsListKr.Add("Hyundai");
carsListKr.Add("Daewoo");

List<string> carsListJp =
  new List <string>();

carsListJp.Add("Honda");
carsListJp.Add("Mazda");
carsListJp.Add("Toyota");

List<string> combined =
  new List<string>();

combined.AddRange(carsListKr);
combined.AddRange(carsListJp);

Console.WriteLine(combined[1]);
Console.WriteLine(combined[4]);

C++

#include <iostream>
#include <vector>
using namespace std;

vector<string> carListKr =
  {"Kia", "Hyundai", "Daewoo"};

vector<string> carListJp =
  {"Honda", "Mazda", "Toyota"};

vector<string> combined;

combined.insert(
  combined.end(),
  carListKr.begin(),
  carListKr.end()
);

combined.insert(
  combined.end(),
  carListJp.begin(),
  carListJp.end()
);

cout << combined[1] << endl;
cout << combined[4] << endl;

Go

import "fmt"

// shorthand way to set up arrays
carsListKr := 
  []string{"Kia", "Hyundai", "Daewoo"};

carsListJp :=
  []string{"Honda", "Mazda", "Toyota"};

// three dot operator includes entire array
combined :=
  append(carsListKr, carsListJp...);

fmt.Println(combined[1]);
fmt.Println(combined[4])

Java

import java.util.Arrays;

String[] carListKr =
  {"Kia", "Hyundai", "Daewoo"};

String[] carListJp =
  {"Honda", "Mazda", "Toyota"};

String[] combined = Arrays.copyOf(
  carListKr, 
  carListKr.length + carListJp.length
);

System.arraycopy(
  carListJp,
  0,
  combined,
  carListKr.length,
  carListJp.length);

System.out.println(combined[1]);
System.out.println(combined[4]);

JavaScript

const carsListKr = ["Kia", "Hyundai", "Daewoo"];
const carsListJp = ["Honda", "Mazda", "Toyota"];
const combined = [...carsListKr, ...carsListJp];

console.log(combined[1]);
console.log(combined[4]);

Kotlin

val carsListKr =
  arrayOf("Kia", "Hyundai", "Daewoo");
val carsListJp =
  arrayOf("Honda", "Mazda", "Toyota");
val combined = carsListKr.plus(carsListJp);

println(combined[1]);
println(combined[4]);

MatLab

carsListKr = ["Kia", "Hyundai", "Daewoo"];
carsListJp = ["Honda", "Mazda", "Toyota"];
combined = horzcat(carsListKr, carsListJp);

disp(combined(2));
disp(combined(5));

PHP

$carsListKr = ['Kia', 'Hyundai', 'Daewoo'];
$carsListJp = ['Honda', 'Mazda', 'Toyota'];
$combined = array_merge($carsListKr, $carsListJp);

echo $combined[1] . "\n";
echo $combined[4];

Python

import numpy as n

carsListKr = ['Kia', 'Hyundai', 'Daewoo']
carsListJp = ['Honda', 'Mazda', 'Toyota']
combined = n.concatenate([carsListKr, carsListJp])

print(combined[1])
print(combined[4])

R

carsListKr <- c("Kia", "Hyundai", "Daewoo")
carsListJp <- c("Honda", "Mazda", "Toyota")
combined = cbind(carsListKr, carsListJp)

print(combined[1])
print(combined[4])

Ruby

carsListKr = ["Kia", "Hyundai", "Daewoo"]
carsListJp = ["Honda", "Mazda", "Toyota"]
combined = carsListKr.concat(carsListJp)

printf(combined[1] + "\n")
printf(combined[4])

Rust

// No Native Support or Implementation

Scala

var carsListKr = Array("Kia", "Hyundai", "Daewoo");
var carsListJp = Array("Honda", "Mazda", "Toyota");
val combined = Array.concat(carsListKr, carsListJp);

println(combined(1));
println(combined(4));

Swift

let carsListKr = ["Kia", "Hyundai", "Daewoo"];
let carsListJp = ["Honda", "Mazda", "Toyota"];
let combined = carsListKr + carsListJp;

print(combined[1]);
print(combined[4]);

TypeScript

const carsListKr:string[] =
  ["Kia", "Hyundai", "Daewoo"];

const carsListJp:string[] =
  ["Honda", "Mazda", "Toyota"];

const combined:string[] = 
  [...carsListKr, ...carsListJp];

console.log(combined[1]);
console.log(combined[4]);

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