Java代码案例44——三种循环计算从1连加到100的正整数和

package xiangmu;
public class Ceshi {
    public static void main(String args[]) {
        // 三种循环计算从1连加到100的正整数和
        // while 循环
        int i = 1;
        int he = 0;
        while(i <= 100) {
            he = he + i;
            i = i + 1;
        }
        System.out.println("1 + 2 + 3 + ... + 99 + 100 = " + he);
        // do...while 循环
        int j = 1;
        int he1 = 0;
        do {
            he1 = he1 + j;
            j = j + 1;
        }while(j <= 100);
        System.out.println("1 + 2 + 3 + ... + 99 + 100 = " + he1);
        // for 循环
        int he2 = 0;
        for(int k = 1; k <= 100; k = k + 1) {
            he2 = he2 + k;
        }
        System.out.println("1 + 2 + 3 + ... + 99 + 100 = " + he2);
    }
}
1 + 2 + 3 + ... + 99 + 100 = 5050
1 + 2 + 3 + ... + 99 + 100 = 5050
1 + 2 + 3 + ... + 99 + 100 = 5050