FavoriteWhat Great .NET Developers Ought To Know

桃扇骨 2021-12-22 12:37 118阅读 0赞

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**Everyone who writes code**

*  Describe the difference between a Thread and a Process?   
    ***\[ANSWER\]:***  
    *1)process is self loadable while thread is depends on operating system  
    2)communication is possible between processes through some mechanism*  
    *e.g. :shared memory, message queues  
    communication is possible between threads directly*  
    *A thread is building block of process, there can be multiple thread or at least one thread per process. Process is self loadable but thread needs a process to run.*
 *  What is a Windows Service and how does its lifecycle differ from a "standard" EXE?  
    ***\[ANSWER\]:**  
    Windows Service applications are long-running applications that are ideal for use in server environments. The applications do not have a user interface or produce any visual output. Any user messages are typically written to the Windows Event Log. Services can be automatically started when the computer is booted. They do not require a logged in user in order to execute and can run under the context of any user including the system. Windows Services are controlled through the Service Control Manager where they can be stopped, paused, and started as needed.*
 *  What is the maximum amount of memory any single process on Windows can address? Is this different than the maximum virtual memory for the system? How would this affect a system design?  
    ***\[ANSWER\]:***  
    *No idea*
 *  What is the difference between an EXE and a DLL?  
    ***\[ANSWER\]:***  
    *An exe is an executable program. A DLL (Dynamic Link Library) is a file that can be loaded and executed by programs dynamically. Basically it's an external code repository for programs. Since usually several different programs reuse the same DLL instead of having that code in their own file, this dramatically reduces required storage space. A synonym for a DLL would be library.*  
    *\[Add\]*  
    *1)  
    DLL: Cannot run independently. Runs with EXE.  
    EXE: Can run independently.  
    2)  
    DLL: Takes up space in memory in processes' memory space, DLL is in-process component.  
    EXE: Takes up space in memory separately, EXE is Out-process.  
    3)  
    DLL: Runs faster than exe.  
    EXE: Slower than DLL.  
    4)  
    DLL: error causes off the application.  
    EXE: can't.  
    5)  
    DLL: Doesn't have own main entry point, handled by other method(s).  
    EXE: Have own entry point, handled by OS.*
 *  What is strong-typing versus weak-typing? Which is preferred? Why?  
    ***\[ANSWER\]:***  
    *In big programs, we will use **strong typing** which can reduce errors at compile time  
    Strong typing provides greater type safety. You might have specially heard it about Data sets being strongly typed, where instead of referring columns as data columns (index).value, you create an XML schema from which you make a data set derived class. Strong typing is preferred as there remains no type ambiguity. Another example is, turning on Option strict in VB, where you have to do explicit type casts. Instead of running into situation where you get a type that you did not expect and try performing an operation on it, you go for strong typing so that such errors are caught during compile time itself.*
 *  Corillian's product is a "Component Container." Name at least 3 component containers that ship now with the Windows Server Family.  
    ***\[ANSWER\]:***  
    *No idea*
 *  What is a PID? How is it useful when troubleshooting a system?  
    ***\[ANSWER\]:***  
    *PID is process id. Have used this mostly to kill processes in UNIX.*
 *  How many processes can listen on a single TCP/IP port?  
    ***\[ANSWER\]:***  
    *One. Only one can capture the incoming packet.*
 *  What is the GAC? What problem does it solve?  
    ***\[ANSWER\]:***  
    *GAC=Global Assembly Cache, solves dll versioning(hell) problem. It's interesting to know how it solves the problem; each assembly is uniquely identified by 4 'things' major version number, minor version, build and revision numbers. For each differing version, the GAC silently creates a subfolder based on a hash of these and places the assembly in it. From a user perspective it seems as if, we are moving the same file in one directory and it doesn't ask if it should overwrite the file!*

**Mid-Level .NET Developer**

*  Describe the difference between Interface-oriented, Object-oriented and Aspect-oriented programming.
 *  Describe what an Interface is and how it’s different from a Class.
 *  What is Reflection?
 *  What is the difference between XML Web Services using ASMX and .NET Remoting using SOAP?
 *  Are the type system represented by XmlSchema and the CLS isomorphic?
 *  Conceptually, what is the difference between early-binding and late-binding?
 *  Is using Assembly.Load a static reference or dynamic reference?
 *  When would using Assembly.LoadFrom or Assembly.LoadFile be appropriate?
 *  What is an Asssembly Qualified Name? Is it a filename? How is it different?
 *  Is this valid? Assembly.Load("foo.dll");
 *  How is a strongly-named assembly different from one that isn’t strongly-named?
 *  Can DateTimes be null?
 *  What is the JIT? What is NGEN? What are limitations and benefits of each?
 *  How does the generational garbage collector in the .NET CLR manage object lifetime? What is non-deterministic finalization?
 *  What is the difference between Finalize() and Dispose()?
 *  How is the using() pattern useful? What is IDisposable? How does it support deterministic finalization?
 *  What does this useful command line do? tasklist /m "mscor\*"
 *  What is the difference between in-proc and out-of-proc?
 *  What technology enables out-of-proc communication in .NET?
 *  When you’re running a component within ASP.NET, what process is it running within on Windows XP? Windows 2000? Windows 2003?

**Senior Developers/Architects**

*  What’s wrong with a line like this? DateTime.Parse(myString);
 *  What are PDBs? Where must they be located for debugging to work?
 *  What is cyclomatic complexity and why is it important?
 *  Write a standard lock() plus “double check” to create a critical section around a variable access.
 *  What is FullTrust? Do GAC’ed assemblies have FullTrust?
 *  What benefit does your code receive if you decorate it with attributes demanding specific Security permissions?
 *  What does this do? gacutil /l | find /i "Corillian"
 *  What does this do? sn -t foo.dll
 *  What ports must be open for DCOM over a firewall? What is the purpose of Port 135?
 *  Contrast OOP and SOA. What are tenets of each?
 *  How does the XmlSerializer work? What ACL permissions does a process using it require?
 *  Why is catch(Exception) almost always a bad idea?
 *  What is the difference between Debug.Write and Trace.Write? When should each be used?
 *  What is the difference between a Debug and Release build? Is there a significant speed difference? Why or why not?
 *  Does JITting occur per-assembly or per-method? How does this affect the working set?
 *  Contrast the use of an abstract base class against an interface?
 *  What is the difference between a.Equals(b) and a == b?
 *  In the context of a comparison, what is object identity versus object equivalence?
 *  How would one do a deep copy in .NET?
 *  Explain current thinking around IClonable.
 *  What is boxing?
 *  Is string a value type or a reference type?
 *  What is the significance of the "PropertySpecified" pattern used by the XmlSerializer? What problem does it attempt to solve?
 *  Why are out parameters a bad idea in .NET? Are they?
 *  Can attributes be placed on specific parameters to a method? Why is this useful?

**C\# Component Developers**

*  Juxtapose the use of override with new. What is shadowing?
 *  Explain the use of virtual, sealed, override, and abstract.
 *  Explain the importance and use of each component of this string: Foo.Bar, Version=2.0.205.0, Culture=neutral, PublicKeyToken=593777ae2d274679d
 *  Explain the differences between public, protected, private and internal.
 *  What benefit do you get from using a Primary Interop Assembly (PIA)?
 *  By what mechanism does NUnit know what methods to test?
 *  What is the difference between: catch(Exception e)\{throw e;\} and catch(Exception e)\{throw;\}
 *  What is the difference between typeof(foo) and myFoo.GetType()?
 *  Explain what’s happening in the first constructor: public class c\{ public c(string a) : this() \{;\}; public c() \{;\} \} How is this construct useful?
 *  What is *this*? Can this be used within a static method?

**ASP.NET (UI) Developers**

*  Describe how a browser-based Form POST becomes a Server-Side event like Button1\_OnClick.
 *  What is a PostBack?
 *  What is ViewState? How is it encoded? Is it encrypted? Who uses ViewState?
 *  What is the <machinekey> element and what two ASP.NET technologies is it used for?
 *  What three Session State providers are available in ASP.NET 1.1? What are the pros and cons of each?
 *  What is Web Gardening? How would using it affect a design?
 *  Given one ASP.NET application, how many application objects does it have on a single proc box? A dual? A dual with Web Gardening enabled? How would this affect a design?
 *  Are threads reused in ASP.NET between reqeusts? Does every HttpRequest get its own thread? Should you use Thread Local storage with ASP.NET?
 *  Is the \[ThreadStatic\] attribute useful in ASP.NET? Are there side effects? Good or bad?
 *  Give an example of how using an HttpHandler could simplify an existing design that serves Check Images from an .aspx page.
 *  What kinds of events can an HttpModule subscribe to? What influence can they have on an implementation? What can be done without recompiling the ASP.NET Application?
 *  Describe ways to present an arbitrary endpoint (URL) and route requests to that endpoint to ASP.NET.
 *  Explain how cookies work. Give an example of Cookie abuse.
 *  Explain the importance of HttpRequest.ValidateInput()?
 *  What kind of data is passed via HTTP Headers?
 *  Juxtapose the HTTP verbs GET and POST. What is HEAD?
 *  Name and describe at least a half dozen HTTP Status Codes and what they express to the requesting client.
 *  How does if-not-modified-since work? How can it be programmatically implemented with ASP.NET?  
    Explain <@OutputCache%> and the usage of VaryByParam, VaryByHeader.
 *  How does VaryByCustom work?
 *  How would one implement ASP.NET HTML output caching, caching outgoing versions of pages generated via all values of q= except where q=5 (as in [http://localhost/page.aspx?q=5][http_localhost_page.aspx_q_5])?

**Developers using XML**

*  What is the purpose of XML Namespaces?
 *  When is the DOM appropriate for use? When is it not? Are there size limitations?
 *  What is the WS-I Basic Profile and why is it important?
 *  Write a small XML document that uses a default namespace and a qualified (prefixed) namespace. Include elements from both namespace.
 *  What is the one fundamental difference between Elements and Attributes?
 *  What is the difference between Well-Formed XML and Valid XML?
 *  How would you validate XML using .NET?
 *  Why is this almost always a bad idea? When is it a good idea? myXmlDocument.SelectNodes("//mynode");
 *  Describe the difference between pull-style parsers (XmlReader) and eventing-readers (Sax)
 *  What is the difference between XPathDocument and XmlDocument? Describe situations where one should be used over the other.
 *  What is the difference between an XML "Fragment" and an XML "Document."
 *  What does it meant to say “the canonical” form of XML?
 *  Why is the XML InfoSet specification different from the Xml DOM? What does the InfoSet attempt to solve?
 *  Contrast DTDs versus XSDs. What are their similarities and differences? Which is preferred and why?
 *  Does System.Xml support DTDs? How?
 *  Can any XML Schema be represented as an object graph? Vice versa?

转载于:https://www.cnblogs.com/hisokahl/archive/2008/06/05/1214662.html

[this link]: http://www.hanselman.com/blog/WhatGreatNETDevelopersOughtToKnowMoreNETInterviewQuestions.aspx
[http_localhost_page.aspx_q_5]: http://localhost/page.aspx?q=5