Java/com/study/demo/test1_3.java

package com.study.demo;

public class test3_1_99 {
    public static void main(String[] args) {
        int[] numbers = new int[99];

        for (int i = 0; i < numbers.length; i++) {
            numbers[i] = i + 1;
        }

        int sum = 0;
        for (int i = 0; i < numbers.length; i++) {
            sum += numbers[i];
        }

        System.out.println("1+2+...+99 的和 = " + sum);
    }
}