Java利用for、while、do...while 循环计算1+3+5+...+99的和

for循环：

public class Forzuoye2 {
    public static void main(String[] args) {
        int sum = 0;
        for (int i = 1; i <= 100; i++) {
            if (i % 2 != 0) {
                sum += i;
            }
        }
        System.out.println("结果为：" + sum);
    }
}

 while循环：

public class Whilezuoye2 {
    public static void main(String[] args) {
        int sum = 0;
        int i = 1;
        while (i <= 100) {
            if (i % 2 == 1)
                sum += i;
            i++;
        }
        System.out.println("结果为：" + sum);
    }
}

 do...while循环：

public class Do_whilezuoye2 {
    public static void main(String[] args) {
        int i = 1;
        int sum = 0;
        do {
            if (i % 2 == 1)
                sum += i;
            i++;
        } while (i <= 100);
        System.out.println("结果为：" + sum);
    }
}