用while，do while,for循环求出一到一百之间的偶数之和

首先是简单的for循环

int sum=0;
        for (int i = 0; i<=100; i++) {
            if (i%2==0)
            sum+=i;

        }
        System.out.println("偶数和为" + sum);
    }

while循环

int a=1;
        int sum=0;
        while (a <=100 ) {
                if (a%2==0) {
                    sum += a;
                }
                a++;
            }  System.out.println("偶数和为" + sum);

do while循环

int a = 1;
        int sum = 0;
        do {
            if (a % 2 == 0) {
                sum += a;
            }
            a++;
        } while (a <= 100) ;
        System.out.println("偶数和为" + sum);*/