這段程式能停止嗎？

  #include <stdio.h><br />#include <stdlib.h></p><p>int main()<br />{<br /> unsigned int i;</p><p> for(i=5; i>=0; i--)<br /> {<br /> printf("This is %d !/n",i);<br /> getch();<br /> }<br /> return 0;<br />}

嘿嘿！試一試吧！

結果是：

This is 5 !
This is 4 !
This is 3 !
This is 2 !
This is 1 !
This is 0 !
This is -1 !
This is -2 !
This is -3 !
This is -4 !

... ...

無符號的整數他永遠是無符號？