# Java Program to Find Union of two Arrays

Here you will get java program to find union of two arrays.

For example we have two sorted arrays a1[] = {2, 3, 5, 11} and a2[] = {4, 7, 9} then union of a1 and a2 will be {2, 3, 4, 5, 7, 9, 11}. A Java program for finding union of two arrays is given below.

Also Read: Java Program to Find Smallest and Largest Element in an Array

## Java Program to Find Union of two Arrays

```package com;

import java.util.Scanner;

class UnionOfArrays
{
public static void main(String...s) {
int i,j,n1,n2;
Scanner sc=new Scanner(System.in); //used to read from keyboard

System.out.print("Enter number of elements of first array:");
n1=sc.nextInt();
System.out.print("Enter number of elements of second array:");
n2=sc.nextInt();

int a1[]=new int[n1];
int a2[]=new int[n2];

System.out.print("\nEnter elements of first array in ascending order:");
for(i=0;i<n1;++i)
a1[i]=sc.nextInt();

System.out.print("\nEnter elements of second array in ascending order:");
for(i=0;i<n2;++i)
a2[i]=sc.nextInt();

i=j=0;
System.out.print("\nUnion of Arrays: ");
while(i<n1&&j<n2)
{
if(a1[i]<a2[j])
{
System.out.print(a1[i]+" ");
i++;
}
else
if(a2[j]<a1[i])
{
System.out.print(a2[j]+" ");
j++;
}
else
{
System.out.print(a1[i]+" ");
i++;
j++;
}
}

if(i<n1)
while(i<n1)
{
System.out.print(a1[i]+" ");
i++;
}

if(j<n2)
while(j<n2)
{
System.out.print(a2[j]+" ");
j++;
}
}
}```

Output

Enter number of elements of first array:3
Enter number of elements of second array:5

Enter elements of first array in ascending order:2 4 6

Enter elements of second array in ascending order:1 3 7 9 12

Union of Arrays: 1 2 3 4 6 7 9 12

### 2 thoughts on “Java Program to Find Union of two Arrays”

1. Дмитрий Згурский

class Program
{
static void Main(string[] args)
{
int[] arrFirst = {2, 3, 5, 11};
int[] arrSecond = {4, 7, 9};
MyClass myClass = new MyClass();
myClass.UnionTwoArrays(arrFirst, arrSecond);
}
}

class MyClass
{
private List doneList = new List();
public void UnionTwoArrays(int[] first, int[] second)
{
foreach (int i in first)
{
}
foreach (int i in second)
{
}
doneList.Sort();
foreach (int i in doneList)
{
Console.WriteLine(i);
}
}
}

2. Enter Number of elements of first Array:6
Enter Number of elements of second Array:6
first array elements in ascending order:
1
2
5
6
6
7
second array elements in ascending order:
2
3
6
7
8
9
Union of Arrays is : 1 2 3 5 6 6 7 8 9