CMI2014-A-06

Question

Suppose we are working with a programming language that supports automatic garbage collection. This means that:

• A. Uninitialized variables are assigned null values.
• B. Unreferenced dynamically allocated memory is added back to free space.
• C. Unreachable $\text{if – then – else}$ branches are pruned.
• D. Expressions where array indices exceed array bounds are flagged.

Answer 1

Garbage collection  also known as automatic memory management, is the automatic recycling of dynamically allocated memory.
Garbage collection is performed by a garbage collector which recycles memory that it can prove will never be used again.
Systems and languages which use garbage collection can be described as garbage-collected.

As long as address space is available in the memory, the runtime continues to allocate space for new objects.
However, memory is not infinite. Eventually the garbage collector must perform a collection in order to free some memory.
The garbage collector's optimizing engine determines the best time to perform a collection, based upon the allocations being made.

So, option B is correct.

Unreferenced dynamically allocated memory is added back to free space.