In Java, it is often necessary to swap adjacent elements in an array. This can be useful for various tasks, such as sorting algorithms or reordering elements. In this blog post, we will discuss how to swap adjacent elements in a Java array efficiently.

Approach

To swap adjacent elements in a Java array, we can use a simple loop that iterates through the array and swaps each pair of adjacent elements. Here’s an example implementation:

public class ArraySwap {
    public static void swapAdjacentElements(int[] arr) {
        for (int i = 0; i < arr.length - 1; i += 2) {
            int temp = arr[i];
            arr[i] = arr[i + 1];
            arr[i + 1] = temp;
        }
    }
}

In the swapAdjacentElements method, we use a for loop to iterate through the array. We initialize the loop variable i to 0 and increment it by 2 in each iteration. This ensures that we only swap adjacent elements.

Inside the loop, we use a temporary variable temp to store the value of the current element arr[i]. Then, we assign the value of the next element arr[i + 1] to arr[i], and finally assign the value of temp to arr[i + 1].

Usage

To use the swapAdjacentElements method, we can create an instance of the ArraySwap class and call the method with our array as an argument. Here’s an example:

public class Main {
    public static void main(String[] args) {
        int[] array = {1, 2, 3, 4, 5};
        ArraySwap.swapAdjacentElements(array);
        
        for (int num : array) {
            System.out.print(num + " ");
        }
    }
}

The output of the above code will be:

2 1 4 3 5

As you can see, the adjacent elements in the array have been swapped.

Conclusion

Swapping adjacent elements in a Java array can be achieved by iterating through the array and swapping each pair of adjacent elements. This approach is simple and efficient, and can be useful in various scenarios.