Hire the Best Developer With These 15 .NET Interview Questions
.Net is a Microsoft software framework that offers a platform for developers to make applications, interfaces, and online software.
The developer evaluates and determines the prerequisites for the application(s), which will often be industry-specific and is also responsible continuous development and support.
Since the initial release of the .Net framework seventeen years ago, it has risen to become the top framework for windows servers both on the cloud and local networks, which explains why there is an increase in demand for .Net developers.
The daily duties of a .Net developer include the execution and development of software applications, developing technical interfaces, developing and testing software prototypes, configuring, upgrading and debugging existing systems, offering technical support, and so on.
.Net developers are normally employed in telecommunications companies, information technology agencies as well as in-house developers for companies in a wide array of industries.
A .Net developer falls in the broader category of careers in computer programming and will typically have a bachelor’s degree in computer science, software engineering, cybernetics or management information systems, though it is not rare to find competent candidates who are self-taught.
Many HR managers have indicated that having certifications in database and software development can be a huge advantage for job seekers, experience in .Net development as well as acquisition of one or more of Microsoft’s .Net certifications such as the Certified Professional Developer.
Considering the important role played by a .NET developer, you want to make sure that you are hiring the best person for the job.
Hiring the wrong person can easily lead to mistakes that might be very costly and time consuming for your organization to fix.
During a job interview, you only have a limited window of time to evaluate a candidate and determine whether they are the right person for the job.
The key to ensuring that you identify the best possible candidate from a group of applicants within such a short time frame is to ask the right questions.
Problem is, which are the right questions for evaluating a developer’s proficiency with the .NET framework?
Most employers are not developers themselves, so they find it challenging to come up with the right questions to ask interviews during the interview
If you are about to hire a .NET developer but are wondering what questions you should ask in order to identify the best candidate, we have compiled for you a list of the top 15 .Net interview questions to make sure you hire the best developer, as well as explanations on what you should expect great candidates to talk about when answering the questions.
1. WHAT IS THE .NET FRAMEWORK AND WHAT ARE ITS COMPONENTS?
This question examines whether the candidate is familiar with the .Net framework, what it does, and its components.
You also have the option of asking this question in two separate parts, that is ‘what is a .Net framework?’ and ‘what are its components?
The candidate should describe the .Net framework as a platform that is used to build a wide array of windows applications.
The framework has an inbuilt list of functions which appear in the form of library, class, and APIs, which are utilized in building, deploying and running of applications and different web services.
The platform supports various languages such as VB.Net, C#, Perl, and Cobol among others.
The components of .Net include .Net Class library, .Net framework profiling, application domain, and common language run-time among others.
The most critical components of .Net frameworks are a common language runtime (CLR) and a class library.
CLR offers the basic blocks for various applications while Class Library comprises class sets that access the common functionality. This functionality is usually distributed within different applications.
2. WHAT IS OOP AND ITS RELATION TO THE .NET FRAMEWORK?
A key feature of the .Net framework is that it supports the Object-oriented programming which is popularly known as the OOP.
By asking this question in an interview, your aims to find out if the developer understands the relationship between the .Net framework and OOP.
A good way that an interviewee might answer this question is by first mentioning that.Net framework supports core languages of OOP which include C++, C#, and Visual Basic.Net. The platform also supports functional programming through F#.
OOP is critical to .Net because it allows developers to make classes which contain properties, events, methods, i.e., logical modules.
Another function of OOP is enabling developers to design modular programs which can later be assembled as applications.
There are four basic features of OOP which are; inheritance, encapsulation, abstraction, and polymorphism.
3. WHAT IS THE DIFFERENCE BETWEEN AN OBJECT AND A CLASS? (AND HOW DO THEY RELATE WITH EACH OTHER)
You can think of class as the template or a building block for object oriented programming.
You can also think of class as a blueprint for the creation of an object.
An object, on the other hand, is a class that has been instantiated.
It is not enough for you to ask interviewees to distinguish between an object and a class simply; the relationship between the two must be established.
The relationship between the two is that class describes the properties and states common to various objects.
4. WHAT IS A DELEGATE IN .NET?
Employers will ask this question to test the candidate’s knowledge of basic and frequently used terms in the profession. A delegate is a type that is used to encapsulate a method to a reference and vice versa.
The process then progresses with the passing of the delegate objects to code which consequently calls the method depending on the signature.
This means that the developer does not have to be aware of the invoked method at the time of compilation.
A delegate usually contains references to multiple and single methods. Delegates can be thought of having a similar function to the C++ pointers and have the benefit of type-safety.
5. WHAT IS ENCAPSULATION?
This question might come before or after the delegate’s question and serves a similar function – to know if the developer is familiar with basic and frequently used professional terms.
Encapsulation is a basic feature of object-oriented programming.
The term refers to the addition of data and method objects to a program to enable the functioning of the object.
A critical thing for interviewees to mention is that the process enables the shielding data from unwarranted access. It binds data and code within an object. This is the basic unit of any system.
In basic terms, encapsulation can be thought of as ‘concealing,’ ‘hiding,’ ‘camouflaging’ an object’s state as protected or private.
The inner workings of the objected are secluded from the other parts of the application. In this way, the object is hidden from another object which could alter the behavior or state of the primary object.
6. EXPLAIN THE DIFFERENCE BETWEEN MANAGED AND UNMANAGED CODE
Such a .Net interview question allows the candidates to show their comprehension of Common Language Runtime, which I will define in the next question. Common language runtime or CLR is a critical component of the .Net framework.
When compiled, code written in either Visual Basic.NET or C# will run on the CLR.
The CLR will then provide functionalities such as memory management, exceptions handling, type checking, and garbage collection for the code.
Since managed code runs within the CLR instead of the operating system, it can be used on any platform, regardless of the operating system being used on that platform.
Unlike managed code, unmanaged code runs directly on the machine code and automatically executed by the operating system. This means that it cannot be run on just any operating system.
It has to be specifically built for a particular operating system. Unmanaged code is usually a product of writing code using languages such as C or C++.
7. WHAT IS COMMON LANGUAGE RUNTIME (CLR)
This is another question asked to test the candidate’s knowledge of basic and frequently used terms in the profession, as well as their familiarity with various components of the .NET framework.
CLR stands for Common Language Runtime and is a run-time environment which forms a critical part of the .Net framework.
It offers the building blocks for various applications. Its individual compiler compiles an application that uses C# and then changes to an intermediate language.
The CLR also performs different functions, including security checks, memory management, thread management, and so on. The CLR also offers a safe environment for application execution.
8. WHAT IS GARBAGE COLLECTION AND WHAT ARE ITS BASIC GENERATIONS?
Garbage collection is a functionality that is provided by the CLR. It is a low-level service that plays a critical role in managing (allocating and releasing) memory for your software.
When one creates an object in the software, the CLR offers the memory for the object in the Managed Heap.
The Managed Heap is an area in memory in which objects are managed and stored. The CLR will always allocate space for new objects provided there is some available memory space within the managed Heap.
When all the memory space in the managed Heap has been used up, the garbage collector steps in to free up some additional memory by checking and deleting any objects that are no longer being accessed by the application.
The benefits of Garbage collection include:
- Memory management for objects
- Automatic reclamation of the object’s memory not in use and or marked for deleting.
The objects within the managed Heap normally get differentiated into three parts called generations. There are three basic sections or generations:
- Generation 0 – This is the first generation in the managed heap used for managing and storing short-lived objects. When the memory is reclaimed, it normally goes by default to generation 0. The ones that remain or survive are then allocated to Generation 1.
- Generation 1 – In this generation, you will find the survived objects from Generation 0 as well as short-lived objects. Those that remain in this section after garbage collection are moved to generation 2.
- Generation 2 – This section contains long-lived objects which remain from the predeceasing generations and are used in the running process.
The garbage collection process identifies the unused memory in the first generation which can provide space for the new object.
The objects are usually made in contagious memory. If adequate memory is found, the search for dead object is stopped, and the allocation process becomes faster.
When the memory is not sufficient, the memory for the objects is reclaimed from those objects that have not been utilized in a long time.
The first step of execution is the seeking of live objects. The objects addresses are then updated. The memory of the dead objects is reclaimed, and the objects are pushed to the proceeding generation.
9. WHAT ARE 3 COMMON ACRONYMS USED IN .NET AND WHAT DO THEY MEAN?
So long as the candidate understands the basics of .Net operations, they will have an easy time answering this one.
This question allows candidates flexibility in picking the terms with which they are most familiar.
In addition, because this question will come much later in the interview, it can give the candidate a chance to get composure after the marathon they must have just participated in.
Some of the most frequently three acronyms used in .Net are CLI, CIL and IL. Below are the meanings for these acronyms:
- IL: This acronym stands for Intermediate Language. This is an OOP language that is used to compile in the .Net framework as a mid-step during the translation of a program into machine code.
- CIL: This stands for Common Intermediate Language which was formerly referred to as Microsoft Intermediate Language or MSIL. This is a programming language which elicits the least level language that human beings can read.
- CLI: This refers to common Language Infrastructure, which is a compiled code library created as an open specification used for versioning, deployment and security uses.
Some other acronyms that are frequently used within the .NET framework environment include
- JIT: Just in Time
- OOP: Object-oriented programming
- CLR: Common Language Runtime
- LINQ: Language Integrated Quarterly etc.
10. WHAT IS ASP.NET MVC?
ASP is an acronym that stands for Active Server pages, which is a component of .Net technologies that also consists of CLR.
An open source web framework, it enables developers to create robust web applications, websites and web services.
In ASP, statement management refers to the sustaining of the object state. In this context, object means web control/page. In ASP.Net, there are two kinds of state management – server side and client side.
On the client side, the information is stored in the page systems, which are simple and reusable objects.
On the server side, the data is stored on the server as it’s easier to manage it on the server instead of client reservation.
11. WHEN SHOULD ONE USE .NET WEB FORMS AS OPPOSED TO ASP.NET MVC?
In the past, the .Net framework was built on web forms.
This effort was meant to build web services using the existing Microsoft Visual tools without the need for developers to know new languages of scripting.
Developers still use some web forms to build simple and quick applications while others are still run as web forms. For contemporary developers, however, the ASP.NET MVC has become the standard.
In the interview, the interview panel should look for a candidate who is able to state and even discuss some of the benefits of the Model-View-Controller pattern.
The most critical feature in the MVS is enabling of the breakdown of application into discrete models, controllers and views, which make easier for testing in the development phase.
12. WHAT IS JSON DATA AND HOW DO DEVELOPERS USE JSON?
The tool is crucial for developers as it enables them to manipulate feeds from other sites which results in faster and easier loading compared to SML or RSS feeds.
JSON enables developers to define the classes to arrays and objects found on JSON text. Other uses of JSON in .net development include serializing value types into JSON text.
13. WHAT IS CAS?
CAS means Code Access Security. The .Net framework offers a security model that intercepts unauthorized access to platforms.
CAS is a component of this security model and is found within the CLR. It allows users to establish permissions for the code at a granular level.
Consequently, the CLR administers the code relying on the permissions available. CAS is only applied to managed code, while unmanaged code performs without it.
When CAS is applied to assemblies, the assembly can be viewed as partially trusted.
Nevertheless, there is a need for assembly checks when a resource is accessed.
The components of CAS include:
- Code Group: Codes are categorized depending on the evidence. Each category of codes possesses particular conditions attached. The conditions that match the assembly are grouped.
- Permissions: There are specific actions that can be executed by a specific code group. When CLR loads an assembly, the codes are matched to code groups, and CLR specifies the actions for the assembly. Some of these permissions include Everything, Execution, The Internet, and Full Trust, among others.
- Evidence: CLR and CAS rely on the assembly evidence in order to decide which permissions to give. The assessment of the assembly offers features about the nooks of the evidence. Some of this evidence includes compose, URL, Zone, Site, Application, Publisher and Hash Value directory.
14. DEFINE LINQ, DIFFERENTIATING BETWEEN IMMEDIATE EXECUTION AND DEFERRED EXECUTION
The term LINQ refers to Language Integrated Query, which is a programming framework that enables developers to manipulate information through a brief but expressive syntax.
The process involves the installation of Microsoft languages which can make formal queries. LINQ is a constitute of C# and can be imported into other languages as a library.
In LINQ, there are deferred execution as well as immediate execution. Deferred execution refers to when a query has not been performed at the time it was initially required to.
The query is assigned to a variable and is stored waiting for execution when the variable is recapitulated. Immediate execution can be enforced for example if the database is frequently updated.
15. WHAT ARE THE DIFFERENCES BETWEEN THE TERMS ‘BOXING’ AND ‘UNBOXING.’
In this question, interviewers are interested in the knowledge of different working terms. They want to know if the interviewee is conversant with such terms and can differentiate them in working.
Boxing is the process of changing a value object into a type object while unboxing is the process of extricating a value type from the object.
Boxing can be thought of as implicit while unboxing, explicit.
During any interview, you as an employer should be aiming at getting the most qualified .Net developer.
Moreover, you want one who is a perfect fit for your organization and whose loyalty and organizational commitment is not in question.
Therefore, you might need to review these questions to come up with a list that will satisfy your organizational needs.
A prudent way to do this would be to refer to another normal interview manual and add some items to this one so as to come up with a comprehensive one to use in the next interview you will have.
Employers and hiring managers are advised to review their interview questions periodically so that they can create questions that are in tandem with the current trends in their fields.
Remember that your .Net developer is also an employee of your firm and must also abide by the other terms and conditions that your regular employees do.
It might not be possible to go through all the topics surrounding the .Net during the constraints of an interview because the framework is vast and comprises a lot of executions and performance activities, but these 15 .Net developer interview questions will help you find a suitable candidate who is well versed with the framework.
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