C# Fundamentals

Question 1

Architect: Why must overflow be considered in balances, counters, and quantities?

Fixed-width types have limits.

int has arbitrary precision Out-of-range results can wrap or throw depending on context Overflow affects only strings The CLR always upgrades int to long

Question 2

Senior: If two variables reference the same mutable class instance, what happens when one changes a property?

Both variables reference one object.

The change is visible through the other reference The property becomes static The runtime clones first The second becomes null

Question 3

Fresher: In static int Add(int a, int b), what does the first int mean?

Look before the method name.

Access modifier Namespace Number of parameters The return type

Question 4

Architect: What is wrong with catch(Exception) followed by doing nothing?

Think hidden failures.

It always improves availability It can hide serious failures and allow invalid state to continue It converts exceptions to null It recompiles the app

Question 5

Architect: How can a static collection retain objects too long?

Reachability matters.

Entries clear after every request GC ignores all static fields It forces objects to disk Its references can keep objects reachable and therefore not collectible

Question 6

Fresher: What is the purpose of condition ? a : b?

It chooses between two expressions.

Catch exceptions Declare a nullable variable Repeat code Return one of two values based on a Boolean condition

Question 7

Fresher: In a traditional C# console application, what is the role of Main?

Think about where execution starts.

It defines the namespace It is the application entry point It must contain every method It performs garbage collection

Question 8

Senior: Why can direct floating-point == comparisons be risky after arithmetic?

Binary floating-point has representation limits.

== is undefined for double All doubles are NaN double is stored as string Expected mathematical values can differ slightly due to representation and rounding

Question 9

Architect: Why doesn't readonly imply deep immutability?

Reference versus referenced object.

It converts objects to strings It has no effect It prevents field reassignment but not mutation of the referenced object readonly works only on int

Question 10

Architect: Why are finalizers usually avoided unless necessary?

Finalization adds lifecycle overhead.

Finalizers cannot contain code They convert classes to structs They require extra runtime processing and delay reclamation They run after every method

Question 11

Senior: What does an init accessor communicate?

Think initialization-only assignment.

Assignment is allowed during initialization but not normal later mutation The property becomes static The property can never be assigned The value is always computed

Question 12

Fresher: What is the difference between = and ==?

One assigns; one compares.

= assigns, while == compares equality = compares while == declares Both assign There is no difference

Question 13

Fresher: When is switch commonly useful?

Think multiple branches.

Only for arrays Only for exceptions Only when creating objects When selecting among several cases based on a value or pattern

Question 14

Fresher: What does public string Name { get; set; } define?

Think properties.

A constant A method A namespace alias An automatically implemented property

Question 15

Architect: Why doesn't Dispose immediately free managed object memory?

Dispose and GC have different roles.

Dispose always calls GC.Collect Dispose releases resources; GC later reclaims managed memory when the object is unreachable Disposed objects become constants Managed memory is never reclaimed