how to sum all numbers in java code example

Example 1: sum of all numbers in array java

int[] a = {10,20,30,40,50};
int sum = IntStream.of(a).sum();
System.out.println("The sum is " + sum);

Example 2: sum of numbers in java

public class SumNatural {

    public static void main(String[] args) {

        int num = 100, sum = 0;

        for(int i = 1; i <= num; ++i)
        {
            // sum = sum + i;
            sum += i;
        }

        System.out.println("Sum = " + sum);
    }
}