1. Introduction

In this post, we will be developing a Java program to merge two sorted String arrays into a single sorted array. This is a common task when dealing with sorted data, and understanding how to perform this merge efficiently is essential.

2. Program Steps

1. Define the main method to serve as the entry point of our program.

2. Initialize two sorted String arrays that we wish to merge.

3. Create a result array of size equal to the sum of the sizes of the two input arrays.

4. Use two pointers technique, one for each input array, and a third one for the result array.

5. Compare the elements at the pointers of the input arrays and insert the smaller one into the result array, then increment the respective pointer.

6. If one of the input arrays is exhausted, insert the remaining elements from the other array into the result array.

7. Once the merge is complete, print out the merged sorted array.

3. Code Program

public class MergeSortedStringArrays {

    public static void main(String[] args) {
        // Step 2: Initialize two sorted String arrays
        String[] arr1 = {"apple", "grape", "orange"};
        String[] arr2 = {"banana", "cherry", "lemon", "mango"};

        // Step 3: Create a result array of size equal to the sum of the sizes of the two input arrays
        String[] result = new String[arr1.length + arr2.length];

        // Step 4: Initialize pointers
        int i = 0, j = 0, k = 0;

        // Step 5: Compare and insert elements into the result array
        while (i < arr1.length && j < arr2.length) {
            if (arr1[i].compareTo(arr2[j]) < 0) {
                result[k++] = arr1[i++];
            } else {
                result[k++] = arr2[j++];
            }
        }

        // Step 6: Insert the remaining elements if any
        while (i < arr1.length) {
            result[k++] = arr1[i++];
        }
        while (j < arr2.length) {
            result[k++] = arr2[j++];
        }

        // Step 7: Print out the merged sorted array
        System.out.print("Merged Sorted Array: ");
        for (String str : result) {
            System.out.print(str + " ");
        }
    }
}

Output:

Merged Sorted Array: apple banana cherry grape lemon mango orange

4. Step By Step Explanation

– Step 1: The main method is defined as the entry point of the program.

– Step 2: We initialize two sorted String arrays arr1 and arr2.

– Step 3: We create a result array whose size is the sum of the sizes of arr1 and arr2.

– Step 4: We initialize three pointers: i and j for arr1 and arr2 respectively, and k for the result array.

– Step 5: We loop through arr1 and arr2, compare the elements at the pointers i and j, insert the smaller one into the result array, and then increment the respective pointer.

– Step 6: If one of the arrays (arr1 or arr2) is exhausted, we insert the remaining elements from the other array into the result array.

– Step 7: Finally, we print out the result array, which is the merged sorted array of the input arrays.

By following this approach, we efficiently merge two sorted String arrays into a single sorted array.