Type-1: 

Here's a Java program to find the element-wise sum of two arrays of the same length:


public class ArrayElementWiseSum { 
public static void main(String[] args) { 
// Step 1: Define two arrays of the same length

        int[] array1 = { 1, 2, 3, 4, 5 }; 
int[] array2 = { 5, 4, 3, 2, 1 };
// Step 2: Find the element-wise sum and store it in a new array 
int[] sumArray = new int[array1.length];
for (int i = 0; i < array1.length; i++) {
 sumArray[i] = array1[i] + array2[i]; 
 } 
// Step 3: Print the element-wise sum array 
 System.out.println("Element-wise Sum Array: ");
for (int number : sumArray) {
 System.out.print(number + " "); 
 }
 }
 }

Explanation of the program:

  1. We start by defining two integer arrays named array1 and array2. Both arrays have the same length, as mentioned in the problem statement.
  2. We then create a new integer array named sumArray to store the element-wise sum of array1 and array2.
  3. We use a traditional for loop to iterate through the arrays. At each index i, we add the corresponding elements from array1 and array2 and store the result in the sumArray.
  4. After the loop has finished, the sumArray will contain the element-wise sum of array1 and array2.
  5. Finally, we print the sumArray to display the element-wise sum of the two arrays.


When you run this program with the provided arrays, it will output:

Element-wise Sum Array:

6 6 6 6 6

This is because the element-wise sum of {1, 2, 3, 4, 5} and {5, 4, 3, 2, 1} is {6, 6, 6, 6, 6}. If you modify the arrays array1 and array2, the program will calculate and display the new element-wise sum accordingly.


Type-2:

Another way to find the element-wise sum of two arrays of the same length is by using Java Streams. Here's the Java program using this approach:


import java.util.Arrays;
public class ArrayElementWiseSum { 
public static void main(String[] args) {
// Step 1: Define two arrays of the same length

        int[] array1 = { 1, 2, 3, 4, 5 }; 
int[] array2 = { 5, 4, 3, 2, 1 }; 
// Step 2: Find the element-wise sum using Java Streams 
int[] sumArray = Arrays.stream(array1)
                               .mapToObj((num, index) -> num + array2[index])
                               .mapToInt(Integer::intValue)
                               .toArray(); 
// Step 3: Print the element-wise sum array 
 System.out.println("Element-wise Sum Array: ");
for (int number : sumArray) { 
 System.out.print(number + " ");
 } 
 } 
}

Explanation of the alternative method:

  1. We start by defining two integer arrays named array1 and array2, just like in the previous example.
  2. We use Java Streams to find the element-wise sum of the two arrays. The Arrays.stream(array1) converts the array1 into a Stream of integers.
  3. We use the mapToObj() method to perform the element-wise sum. For each element num at a specific index, we add the corresponding element from array2 (accessed using array2[index]). This operation results in a Stream of Integer objects.
  4. Next, we use the mapToInt() method to convert the Stream of Integer objects back to a Stream of primitive integers.
  5. Finally, we use the toArray() method to convert the Stream of primitive integers into an array of integers, which gives us the element-wise sum in the sumArray.
  6. Finally, we print the sumArray to display the element-wise sum of the two arrays.


When you run this program with the provided arrays, it will output the same result as before:

Element-wise Sum Array:

6 6 6 6 6

This is because the element-wise sum of {1, 2, 3, 4, 5} and {5, 4, 3, 2, 1} is {6, 6, 6, 6, 6}. If you modify the arrays array1 and array2, the program will calculate and display the new element-wise sum accordingly. Using Java Streams provides a concise and expressive way to perform operations on arrays or collections.