具体执行过程好懵 后加规则也好懵😭😭好心的大哥哥大姐姐们求解答

1,-2

y = 2, a = 1;

// 进入 while

y = 1, a = 1, a = 2; 

y = 0, a = 0, a = 1;

// y = 0, 退出 do-while

y = -1 // 退出 while

y = -2