Java Quiz

Pass with 7 / 10 to unlock your certificate.

1. 1. Which is NOT a primitive type in Java?

   intbooleanStringdouble

2. 2. What does the `final` keyword on a class mean?

   It must be abstractIt cannot be subclassedIt cannot have methodsIt runs last

3. 3. Which collection guarantees insertion order AND fast lookup?

   HashMapTreeMapLinkedHashMapWeakHashMap

4. 4. What is the default value of an uninitialised int field?

   null0undefined-1

5. 5. Which exception is a checked exception?

   NullPointerExceptionIOExceptionArithmeticExceptionClassCastException

6. 6. What does the JVM stand for?

   Java Variable MethodJava Virtual MachineJust Verified ModuleJava Version Manager

7. 7. Which keyword prevents method overriding?

   staticfinalprivateabstract

8. 8. How are Java strings compared by content?

   ==.equals().compareTo() == 0 only===

9. 9. Which feature was introduced in Java 8?

   GenericsLambda expressionsRecordsPattern matching

10. 10. What does `volatile` guarantee?

    AtomicityVisibility across threadsMutual exclusionGarbage collection