3. Assignments

Question 1

What are the values in an array of objects or primitives, when the respective array is instantiated ?

Answer 1

Objects within the array are not instantiated automatically, but all the references get the default value of null. Primitives in an array also get default values.

Question 2

Which variables have default values and which not ?

Answer 2

Instance variables are always initialized with a default value.

Local/automatic/method variables are never given a default value. If you attempt to use one before initializing it, you’ll get a compiler error.

Question 3

What is shadowing ?

Answer 3

Shadowing occurs when two variables with different scopes share the same name. This leads to hard-to-find bugs and hard-to-answer exam questions.

Question 4

How you can run Garbage Collection ?

Answer 4

Only the JVM decides when to run the GC; you can only suggest it.