Читать книгу OCP Oracle Certified Professional Java SE 17 Developer Study Guide - Jeanne Boyarsky - Страница 158

One area the exam might try to trip you up on is using instanceof with incompatible types. For example, Number cannot possibly hold a String value, so the following causes a compilation error:

public void openZoo(Number time) { if(time instanceof String) // DOES NOT COMPILE System.out.print(time); }

If the compiler can determine that a variable cannot possibly be cast to a specific class, it reports an error.