这种办法为什么不可以

public class HelloWorld {
    public static void main(String[] args) {
        int sum = 0;
        int i=1;
       
        do {
           if(i%2==0){
               sum=sum+i;
           }
            i++;
           
            } while (i<=50);
            System.out.println(" 50以内的偶数之和为：" + sum );
        }
    }