?????????在看一本08年出版的書的時候，看到了這樣一個問題，感覺答案很奇怪：

?

?

public class demo_p22 {public static void main(String args[]){int sCook=1,sFish=2;//各技能標記character ch1=new character();if(ch1.haveSkill(sCook))System.out.println(ch1.name+"會烹飪");else System.out.println(ch1.name+"不會烹飪");if(ch1.haveSkill(sFish))System.out.println(ch1.name+"會釣魚");else System.out.println(ch1.name+"不會釣魚");System.out.println("-------------------");ch1.output();System.out.println( ch1.haveSkill(sCook));}
}
class character {String name ="smith";String sex="m";int skill=0;boolean haveSkill (int skillCode){return ((this.skill&skillCode)==skillCode);}void output(){System.out.println(this.skill);}
}

C:\Java\jdk-17.0.11\bin\java.exe "-javaagent:C:\Program Files\JetBrains\IntelliJ IDEA 2022.1.3\lib\idea_rt.jar=2317:C:\Program Files\JetBrains\IntelliJ IDEA 2022.1.3\bin" -Dfile.encoding=UTF-8 -classpath C:\Test\classDemo\out\production\classDemo Java_zhangyu.demo_p22
smith不會烹飪
smith不會釣魚
-------------------
0
false進程已結束,退出代碼0

? ? ? ? 通過對比，果然是書中答案是錯誤的；

總結：

? ? ? ? 1.第一次看到“|”，內心很疑惑，也有一點畏難。認真看了一下，其實就是this.skill==0|1;

void learnSkill(int skillCode){this.skill=this.skill|skillCode;}

??????????return ((0&1)==1);

 boolean haveSkill (int skillCode){return ((this.skill&skillCode)==skillCode);}

????????2. &，|,^?