When you inherit a protected class-level variable, who is it available to? Yes, just leave the class public and make the method sealed. What’s an abstract class? …
Interview Questions
C
1 Whats the implicit name of the parameter that gets passed into the
class set method? Value, and its datatype depends on whatever
variable were changing
2 How do you inherit from a class in C? Place a colon and then the name
of the base class Notice that its double colon in C
3 Does C support multiple inheritance? No, use interfaces instead
4 When you inherit a protected class-level variable, who is it available
to? Classes in the same namespace
5 Are private class-level variables inherited? Yes, but they are not
accessible, so looking at it you can honestly say that they are not
inherited But they are
6 Describe the accessibility modifier protected internal Its available
to derived classes and classes within the same Assembly and naturally
from the base class its declared in
7 C provides a default constructor for me I write a constructor that
takes a string as a parameter, but want to keep the no parameter one
How many constructors should I write? Two Once you write at least one
constructor, C cancels the freebie constructor, and now
you have to
write one yourself, even if theres no implementation in it
8 Whats the top NET class that everything is derived from?
SystemObject
9 Hows method overriding different from overloading? When overriding,
you change the method behavior for a derived class Overloading simply
involves having a method with the same name within the class
10 What does the keyword virtual mean in the method definition? The
method can be over-ridden
11 Can you declare the override method static while the original method
is non-static? No, you cant, the signature of the virtual method must
remain the same, only the keyword virtual is changed to keyword
override
12 Can you override private virtual methods? No, moreover, you cannot
access private methods in inherited classes, have to be protected in
the base class to allow any sort of access
13 Can you prevent your class from being inherited and becoming a base
class for some other classes? Yes, thats what keyword sealed in the
class definition is for The developer trying to derive from your
class will get a message: cannot inherit from Sealed class
WhateverBaseClassName Its the same concept as final class in Java
14 Can you allow class to be inherited, but prevent the method from being
over-ridden? Yes, just leave the class public and make the method
sealed
15 Whats an abstract class? A class that cannot be instantiated A
concept in C known as pure virtual method A class that must be
inherited and have the methods over-ridden Essentially, its a
blueprint for a class without any implementation
16 When do you absolutely have to declare a class as abstract as opposed
to free-willed educated choice or decision based on UML diagram? When
at least one of the methods in the class is abstract When the class
itself is inherited from an abstract class, but not all base abstract
methods have been over-ridden
17 Whats an interface class? Its an abstract class with public abstract
methods all of which must be implemented in the inherited classes
18 Why cant you specify the accessibility modifier for methods inside
the interface? They all must be public Therefore, to prevent you from
getting the false impression that you have any freedom of choice, you
are not allowed to specify any accessibility, its public by default
19 Can you inherit multiple interfaces? Yes, why not
20 And if they have conflicting method names? Its up to you to implement
the method inside your own class, so implementation is left entirely
up to you This might cause a problem on a higher-level scale if
similarly named methods from different interfaces expect different
data, but as far as compiler cares youre okay
21 Whats the difference between an interface and abstract class? In the
interface all methods must be abstract; in the abstract class some
methods can be concrete In the interface no accessibility modifiers
are allowed, which is ok in abstract classes
22 How can you overload a method? Different parameter data types,
different number of parameters, different order of parameters
23 If a base class has a bunch of overloaded constructors, and an
inherited class has another bunch of overloaded constructors, can you
enforce a call from an inherited constructor to an arbitrary base
constructor? Yes, just place a colon, and then keyword base parameter
list to invoke the
appropriate constructor in the overloaded
constructor definition inside the inherited class
24 Whats the difference between SystemString and SystemStringBuilder
classes? SystemString is immutable; SystemStringBuilder was designed
with the purpose of having a mutable string where a variety of
operations can be performed
25 Whats the advantage of using SystemTextStringBuilder over
SystemString? StringBuilder is more efficient in the cases, where a
lot of manipulation is done to the text Strings are immutable, so
each time its being operated on, a new instance is created
26 Can you store multiple data types in SystemArray? No
27 Whats the difference between the SystemArrayCopyTo and
SystemArrayClone? The first one performs a deep copy of the array,
the second one is shallow
28 How can you sort the elements of the array in descending order? By
calling Sort and then Reverse methods
29 Whats the NET datatype that allows the retrieval of data by a unique
key? HashTable
30 Whats class SortedList underneath? A sorted HashTable
31 Will finally block get executed if the exception had not occurred?
Yes
32
Whats the C equivalent of C catch , which was a catch-all
statement for any possible exception? A catch block that catches the
exception of type SystemException You can also omit the parameter
data type in this case and just write catch {}
33 Can multiple catch blocks be executed? No, once the proper catch code
fires off, the control is transferred to the finally block if there
are any, and then whatever follows the finally block
34 Why is it a bad idea to throw your own exceptions? Well, if at that
point you know that an error has occurred, then why not write the
proper code to handle that error instead of passing a new Exception
object to the catch block? Throwing your own exceptions signifies some
design flaws in the project
35 Whats a delegate? A delegate object encapsulates a reference to a
method In C they were referred to as function pointers
36 Whats a multicast delegate? Its a delegate that points to and
eventually fires off several methods
37 Hows the DLL Hell problem solved in NET? Assembly versioning allows
the application to specify not only the library it needs to run which
was
available under Win32, but also the version of the assembly
38 What are the ways to deploy an assembly? An MSI installer, a CAB
archive, and XCOPY command
39 Whats a satellite assembly? When you write a multilingual or multi-
cultural application in NET, and want to distribute the core
application separately from the localized modules, the localized
assemblies that modify the core application are called satellite
assemblies
40 What namespaces are necessary to create a localized application?
SystemGlobalization, SystemResources
41 Whats the difference between // comments, / / comments and ///
comments? Single-line, multi-line and XML documentation comments
42 How do you generate documentation from the C file commented properly
with a command-line compiler? Compile it with a /doc switch
43 Whats the difference between c and code XML documentation tag?
Single line code example and multiple-line code example
44 Is XML case-sensitive? Yes, so Student and student are different
elements
45 What debugging tools come with the NET SDK? CorDBG “ command-line
debugger, and DbgCLR “ graphic debugger Visual Studio
NET uses the
DbgCLR To use CorDbg, you must compile the original C file using the
/debug switch
46 What does the This window show in the debugger? It points to the
object thats pointed to by this reference Objects instance data is
shown
47 What does assert do? In debug compilation, assert takes in a Boolean
condition as a parameter, and shows the error dialog if the condition
is false The program proceeds without any interruption if the
condition is true
48 Whats the difference between the Debug class and Trace class?
Documentation looks the same Use Debug class for debug builds, use
Trace class for both debug and release builds
49 Why are there five tracing levels in SystemDiagnosticsTraceSwitcher?
The tracing dumps can be quite verbose and for some applications that
are constantly running you run the risk of overloading the machine and
the hard drive there Five levels range from None to Verbose, allowing
to fine-tune the tracing activities
50 Where is the output of TextWriterTraceListener redirected? To the
Console or a text file depending on the parameter passed to the
constructor
51 How do you debug an ASPNET Web application? Attach the aspnet_wpexe
process to the DbgClr debugger
52 What are three test cases you should go through in unit testing?
Positive test cases correct data, correct output, negative test
cases broken or missing data, proper handling, exception test cases
exceptions are thrown and caught properly
53 Can you change the value of a variable while debugging a C
application? Yes, if you are debugging via Visual StudioNET, just go
to Immediate window
54 Explain the three services model three-tier application
Presentation UI, business logic and underlying code and data from
storage or other sources
55 What are advantages and disadvantages of Microsoft-provided data
provider classes in ADONET? SQLServerNET data provider is high-speed
and robust, but requires SQL Server license purchased from Microsoft
OLE-DBNET is universal for accessing other sources, like Oracle, DB2,
Microsoft Access and Informix, but its a NET layer on top of OLE
layer, so not the fastest thing in the world ODBCNET is a deprecated
layer provided for backward
compatibility to ODBC engines
56 Whats the role of the DataReader class in ADONET connections? It
returns a read-only dataset from the data source when the command is
executed
57 What is the wildcard character in SQL? Lets say you want to query
database with LIKE for all employees whose name starts with La The
wildcard character is , the proper query with LIKE would involve
˜La
58 Explain ACID rule of thumb for transactions Transaction must be
Atomic it is one unit of work and does not dependent on previous and
following transactions, Consistent data is either committed or roll
back, no in-between case where something has been updated and
something hasnt, Isolated no transaction sees the intermediate
results of the current transaction, Durable the values persist if
the data had been committed even if the system crashes right after
59 What connections does Microsoft SQL Server support? Windows
Authentication via Active Directory and SQL Server authentication
via Microsoft SQL Server username and passwords
60 Which one is trusted and which one is untrusted? Windows
Authentication is trusted
because the username and password are
checked with the Active Directory, the SQL Server authentication is
untrusted, since SQL Server is the only verifier participating in the
transaction
61 Why would you use untrusted verificaion? Web Services might use it, as
well as non-Windows applications
62 What does the parameter Initial Catalog define inside Connection
String? The database name to connect to
63 Whats the data provider name to connect to Access database?
MicrosoftAccess
64 What does Dispose method do with the connection object? Deletes it
from the memory
65 What is a pre-requisite for connection pooling? Multiple processes
must agree that they will share the same connection, where every
parameter is the same, including the security settings
