Quiz: Stack and Heap

📝 Test your knowledge#

Have you really grasped the nuance? This is the moment of truth. Click “See the answer” to check your understanding.

Question 1#

What is the main characteristic of the Stack compared to the Heap in terms of performance?

• A) It is slower but can store more data.
• B) It is much faster to access and allocate.
• C) There is no performance difference.
• D) It is optimized for large objects only.

Question 2#

In C#, where is the value of a local variable of type int stored (for example int age = 25;)?

• A) On the Heap.
• B) In the processor’s registers only.
• C) On the Stack.
• D) Part on the Stack and part on the Heap.

Question 3#

When you instantiate a class (e.g. var user = new User();), what does the variable user located on the Stack contain?

• A) The entire object with all its data.
• B) A copy of the object.
• C) Nothing, the variable is empty until you use it.
• D) The memory address (reference) pointing to the object in the Heap.

Question 4#

If you declare int? score = null;, where is this variable stored?

• A) Only on the Heap because it is null.
• B) Only on the Stack.
• C) It is not stored in memory because it does not exist.
• D) It is an empty reference pointing to the Heap.

Question 5#

Who is responsible for cleaning up memory in the Heap in C#?

• A) The operating system at the end of the program.
• B) The developer, manually.
• C) The method, as soon as it finishes.
• D) The Garbage Collector.

Question 6#

What happens if you copy a variable of a class type (User u2 = u1;) and then modify u2?

• A) It also modifies the object pointed to by u1.
• B) It does not modify u1 because an independent copy was created.
• C) It causes a compilation error.
• D) The original object is deleted and replaced.

Question 7#

What is a StackOverflowException?

• A) When the Heap is full because of objects that are too large.
• B) When you try to access a null variable.
• C) When the Stack is saturated, often by infinite recursive method calls.
• D) When the Garbage Collector can no longer run.

Question 8#

Which statement is true about string? (Nullable Reference Type) in recent C#?

• A) It adds a boolean in memory to indicate whether the string is null.
• B) It moves the string onto the Stack.
• C) It is purely a hint for the compiler; in memory it is identical to string.
• D) It allows the string to be stored without using the Garbage Collector.

Question 9#

Why do we sometimes prefer to use a struct rather than a class for small data objects?

• A) To benefit from inheritance.
• B) To avoid pressure on the Garbage Collector by staying on the Stack.
• C) To be able to set them to null easily.
• D) Because structs have an unlimited size.

Question 10#

In the case User u = null;, what does the variable u physically contain on the Stack?

• A) Absolutely nothing (empty).
• B) A hidden empty object.
• C) An exception.
• D) A special address (usually all bits set to 0).