Simple Java Code to Rotate Array ELements - Left and Right

 Hi Guys, 

In this post, we will see the simplest java program to rotate array elements.

Java program to Right Rotate array elements by N:

package basics;


import java.util.Arrays;


public class MainApp {

	public static void main(String[] args) {

		int[] a1 = { 1, 2, 3, 4, 5, 6, 7 };
		int[] a2 = new int[a1.length];
		
		int rotate = 3;
		//to rotate right
		rotate = a1.length-rotate;

		for (int i = 0; i < a1.length; i++) {
			a2[i] = a1[rotate];
			rotate++;
			if (rotate == a1.length) {
				rotate = a1.length - rotate;
			}
		}
		System.out.println("Before rotate :"+Arrays.toString(a1));
		System.out.println("After rotate :"+Arrays.toString(a2));

	}

}

Output:

 

Before rotate :[1, 2, 3, 4, 5, 6, 7]
After rotate :[5, 6, 7, 1, 2, 3, 4]

Java program to Left Rotate array elements by N:

package basics;


import java.util.Arrays;


public class MainApp {

	public static void main(String[] args) {

		int[] a1 = { 1, 2, 3, 4, 5, 6, 7 };
		int[] a2 = new int[a1.length];
		
		int rotate = 3;

		for (int i = 0; i < a1.length; i++) {
			a2[i] = a1[rotate];
			rotate++;
			if (rotate == a1.length) {
				rotate = a1.length - rotate;
			}
		}
		System.out.println("Before rotate :"+Arrays.toString(a1));
		System.out.println("After rotate :"+Arrays.toString(a2));

	}

}

Output:

Before rotate :[1, 2, 3, 4, 5, 6, 7]
After rotate :[4, 5, 6, 7, 1, 2, 3]