2.How to get the sum of all elements in Java : best ways?

Way 1: To get the sum of all elements in Java: Using normal for loop

To get the sum of all elements in an integer array in Java, you can use a loop to iterate through the array and accumulate the sum of its elements.

Here is an example code snippet:

public class Main{
	public static void main(String[] args) {
		int[] array = { 1, 2, 3, 4, 5 };
		int sum = 0;

		for (int i = 0; i < array.length; i++) {
			sum += array[i];
		}
		System.out.println("Sum of array elements is: " + sum);
	}
}

In this example, we first declare an integer array array with five elements. We then initialize a variable sum to 0, which will be used to accumulate the sum of the array elements.

We then use a for loop to iterate through the array and add each element to the sum variable. Finally, we print out the sum using System.out.println().

The output of this program will be:

Sum of array elements is: 15

Way 2: sum of array elements in java : Using forEach() method.

One alternative method is to use the enhanced for loop, also known as the foreach loop. Here’s an example code snippet:

public class Main{
	public static void main(String[] args) {
		int[] array = { 1, 2, 3, 4, 5 };
		int sum = 0;

		for (int num : array) {
                   sum += num;
                }
		System.out.println("Sum of array elements is: " + sum);
	}
}

In this example, we use the foreach loop to iterate through the array. The loop variable num is used to represent each element of the array in turn. We simply add each num value to the sum variable.

This code produces the same output as the previous example:

Way 3: How to do simple array sum? : Using Arrays.stream() method

Another alternative method is to use the Arrays.stream() method with the sum() method of the IntStream class to calculate the sum of the elements in the array in a single line of code. Here’s an example code snippet:

import java.util.Arrays;
public class Main{
	public static void main(String[] args) {
		int[] array = { 1, 2, 3, 4, 5 };
		int sum = Arrays.stream(array).sum();
		System.out.println("Sum of array elements is: " + sum);
	}
}

In this example, we use the Arrays.stream() method to create a stream of integers from the array, and then we call the sum() method of the IntStream class to calculate the sum of the elements in the stream. The result is stored in the sum variable.

This code also produces the same output as the previous examples:

Way 4: How do you sum integers in Java 8?: Take the array as input from the user.

Here’s an example of how to get the sum of elements in an integer array input by the user using Java 8 features:

import java.util.Scanner;
import java.util.Arrays;

public class Main{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Ask the user for the size of the array
        System.out.print("Enter the size of the array: ");
        int size = scanner.nextInt();

        // Declare an array of the specified size
        int[] array = new int[size];

        // Ask the user to enter the elements of the array
        System.out.print("Enter the elements of the array separated by spaces: ");
        for (int i = 0; i < size; i++) {
            array[i] = scanner.nextInt();
        }

        // Compute the sum of the array elements using Java 8 streams
        int sum = Arrays.stream(array).sum();

        // Print the sum to the console
        System.out.println("The sum of the array elements is: " + sum);

        scanner.close();
    }
}

In this example, we first create a Scanner object to read input from the user. We then prompt the user to enter the size of the array and read the input using scanner.nextInt(). We declare an array of the specified size and prompt the user to enter the elements of the array separated by spaces using a for loop.

Next, we use Java 8 streams to compute the sum of the array elements by calling Arrays.stream(array) to create a stream of the array elements, and then calling the sum() method on the stream. Finally, we print the sum to the console using System.out.println().

Note that we also close the Scanner object at the end of the program to prevent resource leaks.

You can run above all code here just copy and paste.

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