I don't even know what to call what went on - java help on CodeGym

Full code form task link. Hello, Why this didn't work?

public static String getObjectType(Object o) {
       //tutaj wpisz swój kod

       if (o instanceof Cat) {
           return "Cat";
       } else if (o instanceof Tiger) {
           return "Tiger";
       } else if (o instanceof Lion) {
           return "Lion";
      } else if (o instanceof Bull) {
           return "Bull";
       } else if (o instanceof Cow) {
           return "Cow";
       } else return "Animal";
   }

Output: Cat Cat Cat Bull Cow Animal for Tiger and Lion -> error: is always false: and this too don't works:

if (o instanceof Tiger && o instanceof Cat) {
return "Tiger";

error: is always false: And this works.

public static String getObjectType(Object o) {
        //tutaj wpisz swój kod

        if (o instanceof Cat) {
            if (o instanceof Tiger) {
                return "Tiger";
            }
            else if (o instanceof Lion) {
                return "Lion";
            }
            return "Cat";
        } else if (o instanceof Bull) {
            return "Bull";
        } else if (o instanceof Cow) {
            return "Cow";
        } else return "Animal";
    }

Output: Cat Tiger Lion Bull Cow Animal I don't even know what to call what went on here. A nesting queue? The condition is first checked in the inherited class and then the subclass?

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Gellert Varga

Poziom 23 , Szekesfehervar, Hungary

5 września 2021, 12:09

rozwiązanie

Take an example: Animal has a child: Cat. Cat has a child: Tiger. In this case: tigerObject instanceof Tiger: yes tigerObject instanceof Cat: yes tigerObject instanceof Animal: yes tigerObject instanceof Object: yes catObject instanceof Tiger: No catObject instanceof Cat: Yes catObject instanceof Animal: Yes catObject instanceof Object: Yes animalObject instanceof Tiger: No animalObject instanceof Cat: No animalObject instanceof Animal: Yes animalObject instanceof Object: Yes If you first check tigerObject to instanceof Cat, this is true, so the else block will not be executed and your program will print "Cat".