求1加到100的总和

public class Sum {
    public static void main(String[] args) {
        int sum = 0;
        for (int i = 1; i <= 100; i++) {
            sum += i;
        }
        System.out.println("The sum of numbers from 1 to 100 is: " + sum);
    }
}

public class Sum {
    public static void main(String[] args) {
        int n = 100;
        int sum = n * (n + 1) / 2;
        System.out.println("The sum of numbers from 1 to 100 is: " + sum);
    }
}

import java.util.stream.IntStream;

public class Sum {
    public static void main(String[] args) {
        int sum = IntStream.rangeClosed(1, 100).sum();
        System.out.println("The sum of numbers from 1 to 100 is: " + sum);
    }
}