# WAP to Swap Two Adjacent Elements in an Array

What We Are Learn:

Swap Two Adjacent Elements in an Array: This Java program takes an input array containing integers and swaps adjacent elements to create a modified array. It achieves this by iterating through the array with a step size of 2 (i.e., taking every second element) and swapping the positions of each pair of adjacent elements.

### Swap Two Adjacent Elements in an Array

```package com.softwaretestingo.interviewprograms;
public class InterviewPrograms33
{
/*
* Input array- {1,2,3,4,5}
* Output array- {2,1,4,3,5}
*/
public static void main(String[] args)
{
int[] arr = {1,2,3,4,5};
int tmp=0;
for(int i =1;i<arr.length;i+=2)
{
tmp=arr[i];
arr[i]=arr[i-1];
arr[i-1]=tmp;
}
for(int i:arr)
System.out.print(i);
}
}```

Output

`21435`

Alternative Way 1:

This Java program takes an input array containing integers and swaps adjacent elements to create a modified array. The program achieves this using a for loop and conditional statements to handle arrays of even and odd lengths.

```package com.softwaretestingo.interviewprograms;
import java.util.Arrays;
public class InterviewPrograms33_1
{
/*
* Input array- {1,2,3,4,5}
* Output array- {2,1,4,3,5}
*/
public static void main(String[] args)
{
int [] a = {1,2,3,4,5};
if ( a.length % 2 == 1 )
{
for ( int i = 0 ; i<a.length-1; i=i+2)
{
int temp= a[i];
a[i]= a[i+1];
a[i+1]=temp;
}
}
else if (a.length%2==0)
{
for (int i=0; i<a.length; i=i+2)
{
int temp= a[i];
a[i] = a[i+1];
a[i+1]= temp ;
}
}
System.out.println(Arrays.toString(a));
}
}```

Output

`[2, 1, 4, 3, 5]`

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