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  • Efficient algorithm for finding largest eigenpair of small general complex matrix

    - by mklassen
    I am looking for an efficient algorithm to find the largest eigenpair of a small, general (non-square, non-sparse, non-symmetric), complex matrix, A, of size m x n. By small I mean m and n is typically between 4 and 64 and usually around 16, but with m not equal to n. This problem is straight forward to solve with the general LAPACK SVD algorithms, i.e. gesvd or gesdd. However, as I am solving millions of these problems and only require the largest eigenpair, I am looking for a more efficient algorithm. Additionally, in my application the eigenvectors will generally be similar for all cases. This lead me to investigate Arnoldi iteration based methods, but I have neither found a good library nor algorithm that applies to my small general complex matrix. Is there an appropriate algorithm and/or library?

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  • What language has the longest "Hello world" program?

    - by Kip
    In most scripting languages, a "Hello world!" application is very short: print "Hello world" In C++, it is a little more complicated, requiring at least 46 non-whitespace characters: #include <cstdio> int main() { puts("Hello world"); } Java, at 75 non-whitespace characters, is even more verbose: class A { public static void main(String[] args) { System.out.print("Hello world"); } } Are there any languages that require even more non-whitespace characters than Java? Which language requires the most? Notes: I'm asking about the length of the shortest possible "hello world" application in a given language. A newline after "Hello world" is not required. I'm not counting whitespace, but I know there is some language that uses only whitespace characters. If you use that one you can count the whitespace characters.

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  • Prefer extension methods for encapsulation and reusability?

    - by tzaman
    edit4: wikified, since this seems to have morphed more into a discussion than a specific question. In C++ programming, it's generally considered good practice to "prefer non-member non-friend functions" instead of instance methods. This has been recommended by Scott Meyers in this classic Dr. Dobbs article, and repeated by Herb Sutter and Andrei Alexandrescu in C++ Coding Standards (item 44); the general argument being that if a function can do its job solely by relying on the public interface exposed by the class, it actually increases encapsulation to have it be external. While this confuses the "packaging" of the class to some extent, the benefits are generally considered worth it. Now, ever since I've started programming in C#, I've had a feeling that here is the ultimate expression of the concept that they're trying to achieve with "non-member, non-friend functions that are part of a class interface". C# adds two crucial components to the mix - the first being interfaces, and the second extension methods: Interfaces allow a class to formally specify their public contract, the methods and properties that they're exposing to the world. Any other class can choose to implement the same interface and fulfill that same contract. Extension methods can be defined on an interface, providing any functionality that can be implemented via the interface to all implementers automatically. And best of all, because of the "instance syntax" sugar and IDE support, they can be called the same way as any other instance method, eliminating the cognitive overhead! So you get the encapsulation benefits of "non-member, non-friend" functions with the convenience of members. Seems like the best of both worlds to me; the .NET library itself providing a shining example in LINQ. However, everywhere I look I see people warning against extension method overuse; even the MSDN page itself states: In general, we recommend that you implement extension methods sparingly and only when you have to. (edit: Even in the current .NET library, I can see places where it would've been useful to have extensions instead of instance methods - for example, all of the utility functions of List<T> (Sort, BinarySearch, FindIndex, etc.) would be incredibly useful if they were lifted up to IList<T> - getting free bonus functionality like that adds a lot more benefit to implementing the interface.) So what's the verdict? Are extension methods the acme of encapsulation and code reuse, or am I just deluding myself? (edit2: In response to Tomas - while C# did start out with Java's (overly, imo) OO mentality, it seems to be embracing more multi-paradigm programming with every new release; the main thrust of this question is whether using extension methods to drive a style change (towards more generic / functional C#) is useful or worthwhile..) edit3: overridable extension methods The only real problem identified so far with this approach, is that you can't specialize extension methods if you need to. I've been thinking about the issue, and I think I've come up with a solution. Suppose I have an interface MyInterface, which I want to extend - I define my extension methods in a MyExtension static class, and pair it with another interface, call it MyExtensionOverrider. MyExtension methods are defined according to this pattern: public static int MyMethod(this MyInterface obj, int arg, bool attemptCast=true) { if (attemptCast && obj is MyExtensionOverrider) { return ((MyExtensionOverrider)obj).MyMethod(arg); } // regular implementation here } The override interface mirrors all of the methods defined in MyExtension, except without the this or attemptCast parameters: public interface MyExtensionOverrider { int MyMethod(int arg); string MyOtherMethod(); } Now, any class can implement the interface and get the default extension functionality: public class MyClass : MyInterface { ... } Anyone that wants to override it with specific implementations can additionally implement the override interface: public class MySpecializedClass : MyInterface, MyExtensionOverrider { public int MyMethod(int arg) { //specialized implementation for one method } public string MyOtherMethod() { // fallback to default for others MyExtension.MyOtherMethod(this, attemptCast: false); } } And there we go: extension methods provided on an interface, with the option of complete extensibility if needed. Fully general too, the interface itself doesn't need to know about the extension / override, and multiple extension / override pairs can be implemented without interfering with each other. I can see three problems with this approach - It's a little bit fragile - the extension methods and override interface have to be kept synchronized manually. It's a little bit ugly - implementing the override interface involves boilerplate for every function you don't want to specialize. It's a little bit slow - there's an extra bool comparison and cast attempt added to the mainline of every method. Still, all those notwithstanding, I think this is the best we can get until there's language support for interface functions. Thoughts?

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  • No Hibernate Session bound to thread grails

    - by naresh
    Actually we've lot of quartz jobs in our application. For some time all of the jobs work fine. After some time all jobs are throwing the following exception. org.quartz.JobExecutionException: No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here [See nested exception: java.lang.IllegalStateException: No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here] at grails.plugins.quartz.QuartzDisplayJob.execute(QuartzDisplayJob.groovy:37) at org.quartz.core.JobRunShell.run(JobRunShell.java:202) at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573) Caused by: java.lang.IllegalStateException: No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here at grails.plugins.quartz.QuartzDisplayJob.execute(QuartzDisplayJob.groovy:29) ... 2 more

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  • Tables with no Primary Key

    - by Matt Hamilton
    I have several tables whose only unique data is a uniqueidentifier (a Guid) column. Because guids are non-sequential (and they're client-side generated so I can't use newsequentialid()), I have made a non-primary, non-clustered index on this ID field rather than giving the tables a clustered primary key. I'm wondering what the performance implications are for this approach. I've seen some people suggest that tables should have an auto-incrementing ("identity") int as a clustered primary key even if it doesn't have any meaning, as it means that the database engine itself can use that value to quickly look up a row instead of having to use a bookmark. My database is merge-replicated across a bunch of servers, so I've shied away from identity int columns as they're a bit hairy to get right in replication. What are your thoughts? Should tables have primary keys? Or is it ok to not have any clustered indexes if there are no sensible columns to index that way?

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  • Streaming files from EventMachine handler?

    - by Noah
    I am creating a streaming eventmachine server. I'm concerned about avoiding blocking IO or doing anything else to muck up the event loop. From what I've read, ruby's non-blocking IO can be used to stream files in a non-blocking way, or I can call next_tick, but I'm a little unclear about which of these approaches is preferable. Part of the problem is that I have not found a good explanation of non-blocking IO library functions in ruby. Short version: Assuming a long-lived network IO operation, several wall clock minutes of streaming per file, transfer, what is the best way to do this in eventmachine without gumming up the event loop? while 1 do file.read do |bytes| @conn.send_data bytes end end I understand that the above code will block and I'm wondering what to put in its place. Also, I cannot use the FileStreamer class that is part of eventmachine as is, because I need to manipulate the data after it's read but before it's sent. Thanks, Noah

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  • const return value and template instantiation

    - by Rimo
    From Herb Sutter's GotW #6 Return-by-value should normally be const for non-builtin return types. .... Note: Lakos (pg. 618) argues against returning const value, and notes that it is redundant for builtins anyway (for example, returning "const int"), which he notes may interfere with template instantiation. .... While Sutter seems to disagree on whether to return a const value or non-const value when returning an object of a non-built type by value with Lakos, he generally agrees that returning a const value of a built-in type (e.g const int) is not a good idea. While I understand why that is useless because the return value cannot be modified as it is an rvalue, I cannot find an example of how that might interfere with template instantiation. Please give me an example of how having a const qualifier for a return type might interfere with template instantiation.

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  • msvcrt: memory usage goes wild, but not under debugger

    - by al_miro
    I have a C++ code compiled with Intel compiler, 32bit, in MS VC6 mode, so using either msvcrt.dll or msvcrtd.dll. The process makes heavy memory allocation and deallocation. I monitor the memory usage with WMI and look at VirtualSize and WorkingSetSize. with debug runtime (msvcrtd.dll): virtual constant 1.7GB, working constant 1.2GB with non-debug runtime (msvcrt.dll): virtual raising 1.7-- 2.1GB, working raising 1.2-1.4GB with non-debug runtime but under debugger (windbg): virtual constant 1.7GB, working constant At 2.1 GB virtual the process is crashing (as expected). But why would the virtual usage increase only with (non-debug) msvcrt.dll and only if not under debugger? In all cases compilation flags are identical, only runtime libs are different.

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  • Metatool for automatic xml code generation

    - by iceman
    I want to develop a programming tool for developers which can do automatic xml code generation for specifying a GUI design and its controls. The aim is to allow non-programmers specify GUI controls(which in this case perform higher level task unlike WinForms ) from a GUI. So the xml code generated is essentially an internal representation which programmers can understand and further use in any automatic GUI generator. So the workflow is GUI(non-programmers)-xml(for programmers)-GUI(non-programmers). Is there a Microsoft project similar to this?

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  • Excel validation range limits

    - by richardtallent
    When Excel saves a file, it attempts to combine identical Validation settings into a single rule with multiple ranges. This creates one of three issues, depending on the file type you choose to save: When saving as a standard Excel file (Office 2000 BIFF), a maximum of 1024 non-contiguous ranges that can have the same validation setting. When saving as a SpreadsheetML (Office 2002/2003 XML) file, you are limited to the number of non-contiguous ranges that can be represented, comma-delimited in R1C1 format, in 1024 characters. When saving as an Open Office XML (Office 2007 *.xlsx), there is a maximum of 511 non-contiguous ranges that can have the same validation setting. (I don't have Office 2007, I'm using the file converter for Office 2003). Once you bust any of these limits, the remaining ranges with the same Validation settings have their Validation settings wiped. For (1) and (3), Excel warns you that it can't save all of the formatting, but for (2) it does not.

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  • WCF hosted in a Web application and compatibility mode

    - by DotnetDude
    I have a WCF service hosted in a web application (IIS). I need to expose 1 end point over wsHttp and the other over netTcp. I am on a IIS7 environment that makes it possible for me to host non HTTP based services. Anyways, when I browse the .svc file using a browser, I get the error: The service cannot be activated because it does not support ASP.NET compatibility. ASP.NET compatibility is enabled for this application By googling, I realized that WCF runs in two modes - Mixed and ASP.NET compatible. When I apply the attribute [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] However, it appears that once I apply this attribute to the Service Contract implementation, I cannot use a non HTTP binding. How do I set it up so that: I can support non HTTP endpoints I can host the service on a Web app I don't create multiple services one with aspnet compatibility turned on and the other turned off

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  • Scala and the Java Memory Model

    - by Ben Lings
    The Java Memory Model (since 1.5) treats final fields differently to non-final fields. In particular, provided the this reference doesn't escape during construction, writes to final fields in the constructor are guaranteed to be visible on other threads even if the object is made available to the other thread via a data race. (Writes to non-final fields aren't guaranteed to be visible, so if you improperly publish them, another thread could see them in a partially constructed state.) Is there any documentation on how/if the Scala compiler creates final (rather than non-final) backing fields for classes? I've looked through the language specification and searched the web but can't find any definitive answers. (In comparison the @scala.volatile annotation is documented to mark a field as volatile)

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  • REST API unauthenticated requests exception based on the User-Agent

    - by Shay Tsadok
    Hi All, I am developing a REST API that supports two kinds of authentication protocols: login form authentication - for browser based clients. Simple Basic authentication - for non-browser clients. I developed a flow in which unauthenticated requests redirected to the "login form", the problem is that this is an undesired behavior for non-borwser clients! I thought to solve it by decide according to the "User-Agent" what to do: browsers will be redirected to the "login form" and non-browser clients will get the standard 401:Basic Authentication. A. What do you think about this solution? B. Is there a standard way in Java to check if the request came from browser, or do i need to develop this kind of mechanism by my own? Thanks in advance!

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  • Outlook 2007 addins for filtering attachments accordingly to recipients.

    - by Susanta
    My question is that I need to send attached mail to domain users and non domain users. Domain users will receive .lnk of the attached file where as non domain users will receive physical file. Now I am doing by capturing send event of outlook and internally divided mail in two parts for domain users I crated .lnk of the file and attached it and sent to user. Where as for non domain users i attached the physical file and sent to the user. But these things are done by sending two mails internally so I am not able to maintain CC, BCC information. I need to do these things in one mail. So it is possible in outlook addins to filter attachments accordingly to recipients.

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  • Oracle Unique Indexes

    - by Melvin
    I was creating a new table today in 10g when I noticed an interesting behavior. Here is an example of what I did: CREATE TABLE test_table ( field_1 INTEGER PRIMARY KEY ); Oracle will by default, create a non-null unique index for the primary key. I double checked this. After a quick check, I find a unique index name SYS_C0065645. Everything is working as expected so far. Now I did this: CREATE TABLE test_table ( field_1 INTEGER, CONSTRAINT pk_test_table PRIMARY KEY (field_1) USING INDEX (CREATE INDEX idx_test_table_00 ON test_table (field_1))); After describing my newly created index idx_test_table_00, I see that it is non-unique. I tried to insert duplicate data into the table and was stopped by the primary key constraint, proving that the functionality has not been affected. It seems strange to me that Oracle would allow a non-unique index to be used for a primary key constraint. Why is this allowed?

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  • When does a const return type interfere with template instantiation?

    - by Rimo
    From Herb Sutter's GotW #6 Return-by-value should normally be const for non-builtin return types. ... Note: Lakos (pg. 618) argues against returning const value, and notes that it is redundant for builtins anyway (for example, returning "const int"), which he notes may interfere with template instantiation. While Sutter seems to disagree on whether to return a const value or non-const value when returning an object of a non-built type by value with Lakos, he generally agrees that returning a const value of a built-in type (e.g const int) is not a good idea. While I understand why that is useless because the return value cannot be modified as it is an rvalue, I cannot find an example of how that might interfere with template instantiation. Please give me an example of how having a const qualifier for a return type might interfere with template instantiation.

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  • Parameter passed by const reference returned by const reference.

    - by Alien01
    Hello, I was reading C++ Faq Second Edition , faq number 32.08 . FAQ says that parameter passed by const reference and returned by const reference can cause dangling reference. But it is ok if parameter is passed by reference and returned by reference. I got it that it is unsafe in case of const reference but how is it safe in case when parameter is non const reference. Last line of FAQ says "Note that if a function accepts a parameter by non-const reference (for example, f(string& s)), returning a copy of this reference parameter is safe because a temporary cannot be passed by non-const reference." Need some insight on this!!

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  • Python method to remove iterability

    - by Debilski
    Suppose I have a function which can either take an iterable/iterator or a non-iterable as an argument. Iterability is checked with try: iter(arg). Depending whether the input is an iterable or not, the outcome of the method will be different. Not when I want to pass a non-iterable as iterable input, it is easy to do: I’ll just wrap it with a tuple. What do I do when I want to pass an iterable (a string for example) but want the function to take it as if it’s non-iterable? E.g. make that iter(str) fails.

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  • Storing apostrophes, exclamation marks, etc. in mysql database

    - by rein
    I changed from latin1 to utf8. Although all sorts of text was displaying fine I noticed non-english characters were stored in the database as weird symbols. I spent a day trying to fix that and finally now non-english characters display as non-english characters in the database and display the same on the browser. However I noticed that I see apostrophes stored as &#39; and exclamation marks stored as &#33;. Is this normal, or should they be appearing as ' and ! in the database instead? If so, what would I need to do in order to fix that?

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  • Should every class have its own namespace?

    - by thehouse
    Something that has been troubling me for a while: The current wisdom is that types should be kept in a namespace that only contains functions which are part of the type's non-member interface (see C++ Coding Standards Sutter and Alexandrescu or here) to prevent ADL pulling in unrelated definitions. Does this imply that all classes must have a namespace of their own? If we assume that a class may be augmented in the future by the addition of non-member functions, then it can never be safe to put two types in the same namespace as either one of them may introduce non-member functions that could interfere with the other. The reason I ask is that namespaces are becoming cumbersome for me. I'm writing a header-only library and I find myself using classes names such as project::component::class_name::class_name. Their implementations call helper functions but as these can't be in the same namespace they also have to be fully qualified!

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  • GNU General Public License (v2): can a company use the licensed software for free?

    - by EOL
    When a library is released under the GPL v2, can a company use it internally for free? If they develop software based on it, do they have to release it under the GPL, even if they don't distribute it? Can they make money by using (not distributing) internally developed software that links to the GPL'ed library, without any compensation for the author? I am looking for a software license that only allows non-commercial uses (copy, modify, link to); the resulting derived programs must also be free for non-commercial uses. Is there any software license that does this for non-commercial uses, and prevents any commercial use (including using the software in order to make money)? It looks like the Creative Commons licenses are flexible enough to do something close to that, but I've read against using them for software. What do you think?

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  • selecting all text within a div on a single left click with javascript

    - by tstyle
    I have a simple non-clickable link within a div that looks like this: It's meant to be a sharable link that the user can copy paste into other things. For usability purposes, I want a single left click anywhere within the div to select the entire link: I don't know much about, javascript/web programming, so I've tried the following: <div id="share_link" onClick="select_all('share_link')"><%= request.url %></div> and this javascript <script type="text/javascript"> function select_all(id) { document.getElementById(id).focus(); } </script> This doesn't work. I'd like to know what's the simplest thing I should do to achieve what I want. I thought about changing the div to a text input or the text within to be a link, but ideally the content within should be read-only, non-editable, and non-clickable

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  • algorithm to find the three majority elements in an array

    - by Qiang Li
    Let's say there are three elements in a non-sorted array all of which appear more than one-fourth times of the total number of elements. What is the most efficient way to find these elements? Both for non-online and online versions of this question. Thank you! Edit The non-online version I was referring to is: this array is specified in full. The online version means the array elements are coming one at a time. I require the space in addition to time complexity to be tight. disclaimer: THIS IS NOT HOMEWORK! I consider this as research-level question.

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  • Why does this Bash regex match return an Exit Status of "2"?

    - by PreservedMoose
    I'm writing a Bash script that needs to scan for the existence of non-ASCII characters in filenames. I'm using the POSIX bracket regex syntax to match the non-ASCII characters, but for some reason, when I test for the match in an if/then statement, the test always returns an Exit Status of 2, and never matches my test string. Here's the code in question: FILEREQ_SOURCEFILE="Filename–WithNonAScII-Charàcters-05sec_23.98.mov" REGEX_MATCH_NONASCII="[^[:ascii:]]" if [[ $FILEREQ_SOURCEFILE =~ $REGEX_MATCH_NONASCII ]]; then echo "Exit Status: $?" echo "Matched!" else echo "Exit Status: $?" echo "No Match" fi This code always returns: Exit Status: 2 No Match I've read and re-read the bash-hackers.org explanation of how regex matching works, as well as this previous question on SO regarding matching non-ASCII characters, but for the life of me, I can't get this to work. What am I missing here?

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  • These are few objective type questions which i was not able to find the solution [closed]

    - by Tarun
    1. Which of the following advantages does System.Collections.IDictionaryEnumerator provide over System.Collections.IEnumerator? a. It adds properties for direct access to both the Key and the Value b. It is optimized to handle the structure of a Dictionary. c. It provides properties to determine if the Dictionary is enumerated in Key or Value order d. It provides reverse lookup methods to distinguish a Key from a specific Value 2. When Implementing System.EnterpriseServices.ServicedComponent derived classes, which of the following statements are true? a. Enabling object pooling requires an attribute on the class and the enabling of pooling in the COM+ catalog. b. Methods can be configured to automatically mark a transaction as complete by the use of attributes. c. You can configure authentication using the AuthenticationOption when the ActivationMode is set to Library. d. You can control the lifecycle policy of an individual instance using the SetLifetimeService method. 3. Which of the following are true regarding event declaration in the code below? class Sample { event MyEventHandlerType MyEvent; } a. MyEventHandlerType must be derived from System.EventHandler or System.EventHandler<TEventArgs> b. MyEventHandlerType must take two parameters, the first of the type Object, and the second of a class derived from System.EventArgs c. MyEventHandlerType may have a non-void return type d. If MyEventHandlerType is a generic type, event declaration must use a specialization of that type. e. MyEventHandlerType cannot be declared static 4. Which of the following statements apply to developing .NET code, using .NET utilities that are available with the SDK or Visual Studio? a. Developers can create assemblies directly from the MSIL Source Code. b. Developers can examine PE header information in an assembly. c. Developers can generate XML Schemas from class definitions contained within an assembly. d. Developers can strip all meta-data from managed assemblies. e. Developers can split an assembly into multiple assemblies. 5. Which of the following characteristics do classes in the System.Drawing namespace such as Brush,Font,Pen, and Icon share? a. They encapsulate native resource and must be properly Disposed to prevent potential exhausting of resources. b. They are all MarshalByRef derived classes, but functionality across AppDomains has specific limitations. c. You can inherit from these classes to provide enhanced or customized functionality 6. Which of the following are required to be true by objects which are going to be used as keys in a System.Collections.HashTable? a. They must handle case-sensitivity identically in both the GetHashCode() and Equals() methods. b. Key objects must be immutable for the duration they are used within a HashTable. c. Get HashCode() must be overridden to provide the same result, given the same parameters, regardless of reference equalityl unless the HashTable constructor is provided with an IEqualityComparer parameter. d. Each Element in a HashTable is stored as a Key/Value pair of the type System.Collections.DictionaryElement e. All of the above 7. Which of the following are true about Nullable types? a. A Nullable type is a reference type. b. A Nullable type is a structure. c. An implicit conversion exists from any non-nullable value type to a nullable form of that type. d. An implicit conversion exists from any nullable value type to a non-nullable form of that type. e. A predefined conversion from the nullable type S? to the nullable type T? exists if there is a predefined conversion from the non-nullable type S to the non-nullable type T 8. When using an automatic property, which of the following statements is true? a. The compiler generates a backing field that is completely inaccessible from the application code. b. The compiler generates a backing field that is a private instance member with a leading underscore that can be programmatically referenced. c. The compiler generates a backing field that is accessible via reflection d. The compiler generates a code that will store the information separately from the instance to ensure its security. 9. Which of the following does using Initializer Syntax with a collection as shown below require? CollectionClass numbers = new CollectionClass { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; a. The Collection Class must implement System.Collections.Generic.ICollection<T> b. The Collection Class must implement System.Collections.Generic.IList<T> c. Each of the Items in the Initializer List will be passed to the Add<T>(T item) method d. The items in the initializer will be treated as an IEnumerable<T> and passed to the collection constructor+K110 10. What impact will using implicitly typed local variables as in the following example have? var sample = "Hello World"; a. The actual type is determined at compilation time, and has no impact on the runtime b. The actual type is determined at runtime, and late binding takes effect c. The actual type is based on the native VARIANT concept, and no binding to a specific type takes place. d. "var" itself is a specific type defined by the framework, and no special binding takes place 11. Which of the following is not supported by remoting object types? a. well-known singleton b. well-known single call c. client activated d. context-agile 12. In which of the following ways do structs differ from classes? a. Structs can not implement interfaces b. Structs cannot inherit from a base struct c. Structs cannot have events interfaces d. Structs cannot have virtual methods 13. Which of the following is not an unboxing conversion? a. void Sample1(object o) { int i = (int)o; } b. void Sample1(ValueType vt) { int i = (int)vt; } c. enum E { Hello, World} void Sample1(System.Enum et) { E e = (E) et; } d. interface I { int Value { get; set; } } void Sample1(I vt) { int i = vt.Value; } e. class C { public int Value { get; set; } } void Sample1(C vt) { int i = vt.Value; } 14. Which of the following are characteristics of the System.Threading.Timer class? a. The method provided by the TimerCallback delegate will always be invoked on the thread which created the timer. b. The thread which creates the timer must have a message processing loop (i.e. be considered a UI thread) c. The class contains protection to prevent reentrancy to the method provided by the TimerCallback delegate d. You can receive notification of an instance being Disposed by calling an overload of the Dispose method. 15. What is the proper declaration of a method which will handle the following event? Class MyClass { public event EventHandler MyEvent; } a. public void A_MyEvent(object sender, MyArgs e) { } b. public void A_MyEvent(object sender, EventArgs e) { } c. public void A_MyEvent(MyArgs e) { } d. public void A_MyEvent(MyClass sender,EventArgs e) { } 16. Which of the following scenarios are applicable to Window Workflow Foundation? a. Document-centric workflows b. Human workflows c. User-interface page flows d. Builtin support for communications across multiple applications and/or platforms e. All of the above 17. When using an automatic property, which of the following statements is true? a. The compiler generates a backing field that is completely inaccessible from the application code. b. The compiler generates a backing field that is a private instance member with a leading underscore that can be programmatically referenced. c. The compiler generates a backing field that is accessible via reflection d. The compiler generates a code that will store the information separately from the instance to ensure its security. 18 While using the capabilities supplied by the System.Messaging classes, which of the following are true? a. Information must be explicitly converted to/from a byte stream before it uses the MessageQueue class b. Invoking the MessageQueue.Send member defaults to using the System.Messaging.XmlMessageFormatter to serialize the object. c. Objects must be XMLSerializable in order to be transferred over a MessageQueue instance. d. The first entry in a MessageQueue must be removed from the queue before the next entry can be accessed e. Entries removed from a MessageQueue within the scope of a transaction, will be pushed back into the front of the queue if the transaction fails. 19. Which of the following are true about declarative attributes? a. They must be inherited from the System.Attribute. b. Attributes are instantiated at the same time as instances of the class to which they are applied. c. Attribute classes may be restricted to be applied only to application element types. d. By default, a given attribute may be applied multiple times to the same application element. 20. When using version 3.5 of the framework in applications which emit a dynamic code, which of the following are true? a. A Partial trust code can not emit and execute a code b. A Partial trust application must have the SecurityCriticalAttribute attribute have called Assert ReflectionEmit permission c. The generated code no more permissions than the assembly which emitted it. d. It can be executed by calling System.Reflection.Emit.DynamicMethod( string name, Type returnType, Type[] parameterTypes ) without any special permissions Within Windows Workflow Foundation, Compensating Actions are used for: a. provide a means to rollback a failed transaction b. provide a means to undo a successfully committed transaction later c. provide a means to terminate an in process transaction d. achieve load balancing by adapting to the current activity 21. What is the proper declaration of a method which will handle the following event? Class MyClass { public event EventHandler MyEvent; } a. public void A_MyEvent(object sender, MyArgs e) { } b. public void A_MyEvent(object sender, EventArgs e) { } c. public void A_MyEvent(MyArgs e) { } d. public void A_MyEvent(MyClass sender,EventArgs e) { } 22. Which of the following controls allows the use of XSL to transform XML content into formatted content? a. System.Web.UI.WebControls.Xml b. System.Web.UI.WebControls.Xslt c. System.Web.UI.WebControls.Substitution d. System.Web.UI.WebControls.Transform 23. To which of the following do automatic properties refer? a. You declare (explicitly or implicitly) the accessibility of the property and get and set accessors, but do not provide any implementation or backing field b. You attribute a member field so that the compiler will generate get and set accessors c. The compiler creates properties for your class based on class level attributes d. They are properties which are automatically invoked as part of the object construction process 24. Which of the following are true about Nullable types? a. A Nullable type is a reference type. b. An implicit conversion exists from any non-nullable value type to a nullable form of that type. c. A predefined conversion from the nullable type S? to the nullable type T? exists if there is a predefined conversion from the non-nullable type S to the non-nullable type T 25. When using an automatic property, which of the following statements is true? a. The compiler generates a backing field that is completely inaccessible from the application code. b. The compiler generates a backing field that is accessible via reflection. c. The compiler generates a code that will store the information separately from the instance to ensure its security. 26. When using an implicitly typed array, which of the following is most appropriate? a. All elements in the initializer list must be of the same type. b. All elements in the initializer list must be implicitly convertible to a known type which is the actual type of at least one member in the initializer list c. All elements in the initializer list must be implicitly convertible to common type which is a base type of the items actually in the list 27. Which of the following is false about anonymous types? a. They can be derived from any reference type. b. Two anonymous types with the same named parameters in the same order declared in different classes have the same type. c. All properties of an anonymous type are read/write. 28. Which of the following are true about Extension methods. a. They can be declared either static or instance members b. They must be declared in the same assembly (but may be in different source files) c. Extension methods can be used to override existing instance methods d. Extension methods with the same signature for the same class may be declared in multiple namespaces without causing compilation errors

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