Memory

Question 1

How does java allocate memory to variables?

Answer 1

When a declaration of r is processed, a block of memory is allocated to r, at a certain address, which is large enough to store a reference to an object of class r.

Question 2

What happens when an object is created?

Answer 2

A block of free memory large enough to store the object (its attributes and methods) is allocated to this object.

Question 3

Is an object stored directly in a variable?

Answer 3

Not necessarily, it could be a reference variable which would refer to an object could be stored in a variable.

Question 4

What are the Java data types?

Answer 4

Primitive and non-primitive (classes).

Question 5

What are the 8 primitive Java data types:

Answer 5

boolean, char, byte, short, int, long, float, double

Question 6

What’s the difference between a primitive and non-primitive type?

Answer 6

A primitive type stores a value, a non-primitive type stores an address

Question 7

When comparing objects, what’s the difference between “==” and “.equals()”?

Answer 7

== checks if both objects are pointing to the same memory location, whereas .equals() evaluates to the comparison of values in the objects.