Scala program to merge two arrays or array buffer

1) Using the concat() method

In Scala, there is a method named concat() that is used to concatenate two arrays.

Syntax:

    concat(array_1, array_2)

This method returns an array which is a concatenated array.

Program to concatenate two arrays using concat() method

object myObject {
    def main(args: Array[String]) {
        val array1 = Array(56, 12, 67) 
        print("Array 1: ")  
        for(i <- 0 to array1.length-1)
            print(array1(i)+" ")

        val array2 = Array(83, 45, 90) 
        print("\nArray 2: ")  
        for(i <- 0 to array2.length-1)
            print(array2(i)+" ")

        val array3 = Array.concat(array1, array2) 

        print("\nMerged array: ")  
        for(i <- 0 to array3.length-1)
            print(array3(i)+" ") 
    }
}

Output

Array 1: 56 12 67 
Array 2: 83 45 90 
Merged array: 56 12 67 83 45 90 

2) Using the ++ method

To merge two arrays into one ++ method can also be used.

Syntax:

    array1 ++ array2 

This will return the merge array.

Program to concatenate two arrays using ++ method

object myObject {
    def main(args: Array[String]) {
        val array1 = Array("Include", "Help") 
        print("Array 1: ")  
        for(i <- 0 to array1.length-1)
            print(array1(i)+" ")

        val array2 = Array("Learn", "Programming") 
        print("\nArray 2: ")  
        for(i <- 0 to array2.length-1)
            print(array2(i)+" ")

        val array3 = array1 ++ array2
        print("\nMerged array: ")  
        for(i <- 0 to array3.length-1)
            print(array3(i)+" ") 
    }
}

Output

Array 1: Include Help 
Array 2: Learn Programming 
Merged array: Include Help Learn Programming 

Merging two mutable arrays (arrayBuffers)

We can assign the concatenated array to any of the existing arrays when they are mutable. Both methods, concat() and ++ apply to ArrayBuffer also. A method assignment method can also be applied to the ArrayBuffer which is +=.

Program to concatenate two ArrayBuffer into one

import scala.collection.mutable.ArrayBuffer

object myObject {
    def main(args: Array[String]) {
        val array1 = ArrayBuffer(12, 43, 54) 
        print("Array 1: ")  
        for(i <- 0 to array1.length-1)
            print(array1(i)+" ")

        val array2 = ArrayBuffer(465, 787, 99) 
        print("\nArray 2: ")  
        for(i <- 0 to array2.length-1)
            print(array2(i)+" ")

        array1 ++= array2
        
        print("\nMerged array: ")  
        for(i <- 0 to array1.length-1)
            print(array1(i)+" ") 
    }
}

Output

Array 1: 12 43 54 
Array 2: 465 787 99 
Merged array: 12 43 54 465 787 99