因為這里的case的值是char類型，對應(yīng)上面today的值。你把上面的today定義成String類型即可。

如：

public?class?HelloWorld?{
????public?static?void?main(String[]?args)?{
??????String?today="日";
??????switch(today){
?????????case"一":
?????????case"三":
?????????case"五":
????????????System.out.println("吃包子");
????????????break;
?????????case"二":
?????????case"四":
?????????case"六":
?????????????System.out.println("吃油條");
?????????????break;
?????????default:
?????????????System.out.println("吃主席套餐");
??}???
????????
?}
}