how to add the last area of an array in java

To add the last element of an array in Java, you can use the length property of the array to access the last element and then use the + operator to add it to a sum.

Here's an example of how you could add the last element of an array in Java:

int[] numbers = {1, 2, 3, 4, 5};
int sum = 0;
sum += numbers[numbers.length - 1];
System.out.println(sum);

In this example, the numbers array is initialized with five elements using an array literal. The sum variable is initialized with the value 0. The last element of the numbers array is accessed using the length property and the - 1 index, and it is added to the sum variable using the += operator. Finally, the sum variable is printed using the println method.

The output of this example would be the following number:

5

Keep in mind that this approach works for arrays of any length and any type of elements. You can use a similar approach to add other elements of the array, by using a different index or using a loop to iterate over the elements of the array.

Alternatively, you can use the Arrays.stream method to create a stream of the array elements and then use the reduce method to perform the addition. Here's an example of how you could use the Arrays.stream method to add the last element of an array:

import java.util.Arrays;

public class Main {
  public static void main(String[] args) {
    int[] numbers = {1, 2, 3, 4, 5};
    int sum = Arrays.stream(numbers).reduce(0, (a, b) -> a + b);
    System.out.println(sum);
  }
}

In this example, the Arrays.stream method is used to create a stream of the numbers array. The reduce method is then used to perform the addition of the elements in the stream, by specifying an initial value of 0 and a lambda function that takes two elements a and b and returns their sum. Finally, the sum variable is printed using the println method.

The output of this example would be the same as the previous example:

15

Keep in mind that the Arrays.stream method is part of the java.util package, which is included in the standard Java SE library. You can use a similar approach to add other types of elements, by replacing the type of the array and the lambda function with the appropriate types.