Q45. Is sizeof a keyword?
The sizeof operator is not a keyword.

Q46. What are wrapped classes?
Wrapped classes are classes that allow primitive types to be accessed as objects.

Q47. Does garbage collection guarantee that a program will not run out of memory?
Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection

Q48. What restrictions are placed on the location of a package statement within a source code file?
A package statement must appear as the first line in a source code file (excluding blank lines and comments).