Search Results

Search found 16554 results on 663 pages for 'programmers identity'.

Page 175/663 | < Previous Page | 171 172 173 174 175 176 177 178 179 180 181 182  | Next Page >

  • What is Atomicity?

    - by James Jeffery
    I'm really struggling to find a concrete, easy to grasp, explanation of Atomicity. My understanding thus far is that to ensure an operation is atomic you wrap the critical code in a locker. But that's about as much as I actually understand. Definitions such as the one below make no sense to me at all. An operation during which a processor can simultaneously read a location and write it in the same bus operation. This prevents any other processor or I/O device from writing or reading memory until the operation is complete. Atomic implies indivisibility and irreducibility, so an atomic operation must be performed entirely or not performed at all. What does the last sentence mean? Is the term indivisibility relating to mathematics or something else? Sometimes the jargon with these topics confuse more than they teach.

    Read the article

  • Builder Pattern: When to fail?

    - by skiwi
    When implementing the Builder Pattern, I often find myself confused with when to let building fail and I even manage to take different stands on the matter every few days. First some explanation: With failing early I mean that building an object should fail as soon as an invalid parameter is passed in. So inside the SomeObjectBuilder. With failing late I mean that building an object only can fail on the build() call that implicitely calls a constructor of the object to be built. Then some arguments: In favor of failing late: A builder class should be no more than a class that simply holds values. Moreover, it leads to less code duplication. In favor of failing early: A general approach in software programming is that you want to detect issues as early as possible and therefore the most logical place to check would be in the builder class' constructor, 'setters' and ultimately in the build method. What is the general concensus about this?

    Read the article

  • R vs Python for data analysis

    - by The_Cthulhu_Kid
    I have been programming for about a year and I am really interested in data analysis and machine learning. I am taking part in a couple of online courses and am reading a couple of books. Everything I am doing uses either R or Python and I am looking for suggestions on whether or not I should concentrate on one language (and if so which) or carry on with both; do they complement each other? -- I should mention that I use C# in school but am familiar with Python through self-study.

    Read the article

  • How is time calculation performed by a computer?

    - by Jorge Mendoza
    I need to add a certain feature to a module in a given project regarding time calculation. For this specific case I'm using Java and reading through the documentation of the Date class I found out the time is calculated in milliseconds starting from January 1, 1970, 00:00:00 GMT. I think it's safe to assume there is a similar "starting date" in other languages so I guess the specific implementation in Java doesn't matter. How is the time calculation performed by the computer? How does it know exactly how many milliseconds have passed from that given "starting date and time" to the current date and time?

    Read the article

  • Should a senior developer refuse to take paper exams during an interview?

    - by ??? Shengyuan Lu
    I found that many senior developers refuse to do paper exams in interviews. They regard the exam as a kind of humiliation, because they think that "They don't trust my programming ability even if I have five years working experience... only junior staff need take a paper exam...". However, Joel insists: 11. Do new candidates write code during their interview? Would you hire a magician without asking them to show you some magic tricks? Of course not. Is it justifiable if a senior developer refuses to take a paper exam in an interview?

    Read the article

  • What C++ coding standard do you use?

    - by gablin
    For some time now, I've been unable to settle on a coding standard and use it concistently between projects. When starting a new project, I tend to change some things around (add a space there, remove a space there, add a line break there, an extra indent there, change naming conventions, etc.). So I figured that I might provide a piece of sample code, in C++, and ask you to rewrite it to fit your standard of coding. Inspiration is always good, I say. ^^ So here goes: #ifndef _DERIVED_CLASS_H__ #define _DERIVED_CLASS_H__ /** * This is an example file used for sampling code layout. * * @author Firstname Surname */ #include <stdio> #include <string> #include <list> #include "BaseClass.h" #include "Stuff.h" /** * The DerivedClass is completely useless. It represents uselessness in all its * entirety. */ class DerivedClass : public BaseClass { //////////////////////////////////////////////////////////// // CONSTRUCTORS / DESTRUCTORS //////////////////////////////////////////////////////////// public: /** * Constructs a useless object with default settings. * * @param value * Is never used. * @throws Exception * If something goes awry. */ DerivedClass (const int value) : uselessSize_ (0) {} /** * Constructs a copy of a given useless object. * * @param object * Object to copy. * @throws OutOfMemoryException * If necessary data cannot be allocated. */ ItemList (const DerivedClass& object) {} /** * Destroys this useless object. */ ~ItemList (); //////////////////////////////////////////////////////////// // PUBLIC METHODS //////////////////////////////////////////////////////////// public: /** * Clones a given useless object. * * @param object * Object to copy. * @return This useless object. */ DerivedClass& operator= (const DerivedClass& object) { stuff_ = object.stuff_; uselessSize_ = object.uselessSize_; } /** * Does absolutely nothing. * * @param useless * Pointer to useless data. */ void doNothing (const int* useless) { if (useless == NULL) { return; } else { int womba = *useless; switch (womba) { case 0: cout << "This is output 0"; break; case 1: cout << "This is output 1"; break; case 2: cout << "This is output 2"; break; default: cout << "This is default output"; break; } } } /** * Does even less. */ void doEvenLess () { int mySecret = getSecret (); int gather = 0; for (int i = 0; i < mySecret; i++) { gather += 2; } } //////////////////////////////////////////////////////////// // PRIVATE METHODS //////////////////////////////////////////////////////////// private: /** * Gets the secret value of this useless object. * * @return A secret value. */ int getSecret () const { if ((RANDOM == 42) && (stuff_.size() > 0) || (1000000000000000000 > 0) && true) { return 420; } else if (RANDOM == -1) { return ((5 * 2) + (4 - 1)) / 2; } int timer = 100; bool stopThisMadness = false; while (!stopThisMadness) { do { timer--; } while (timer > 0); stopThisMadness = true; } } //////////////////////////////////////////////////////////// // FIELDS //////////////////////////////////////////////////////////// private: /** * Don't know what this is used for. */ static const int RANDOM = 42; /** * List of lists of stuff. */ std::list <Stuff> stuff_; /** * Specifies the size of this object's uselessness. */ size_t uselessSize_; }; #endif

    Read the article

  • Terminology: .NET C++ vs. traditional C++

    - by Mike Clark
    Hello. I've recently been working with a team that's using both .NET C++ and pre-.NET C++. I fully understand the technical differences between the two technologies. However, I sometimes feel like I'm floundering when it comes to the terminology used to differentiate the two. Example: Say we have two projects: ProjectA contains "C++" code that builds a .NET assembly DLL. ProjectB contains Visual C++ code that builds a traditional native Windows DLL. What is the best way to succinctly and terminologically draw a distinction between the two projects? Again, I'm not asking for an in-depth technical description of the differences between the two technologies. I'm just looking for names and labels. This is how I might try to make the distinction when talking to someone about Project A and Project B: "ProjectA is a managed .NET C++ project" and ProjectB is an unmanaged Visual C++ DLL project." However I am not at all certain that this terminology is ideal, or even correct. Please describe what you feel the ideal language to use in this situation (or similar situations) might be. Feel free to motivate your answer.

    Read the article

  • How to avoid big and clumpsy UITableViewController on iOS?

    - by Johan Karlsson
    I have a problem when implementing the MVC-pattern on iOS. I have searched the Internet but seems not to find any nice solution to this problem. Many UITableViewController implementations seems to be rather big. Most example I have seen lets the UITableViewController implement UITableViewDelegate and UITableViewDataSource. These implementations are a big reason why UITableViewControlleris getting big. One solution would be to create separate classes that implements UITableViewDelegate and UITableViewDataSource. Of course these classes would have to have a reference to the UITableViewController. Are there any drawbacks using this solution? In general I think you should delegate the functionality to other "Helper" classes or similar, using the delegate pattern. Are there any well established ways of solving this problem? I do not want the model to contain to much functionality, nor the view. A believe that the logic should really be in the controller class, since this is one of the cornerstones of the MVC-pattern. But the big question is; How should you divide the controller of a MVC-implementation into smaller manageable pieces? (Applies to MVC in iOS in this case) There might be a general pattern for solving this, although I am specifically looking for a solution for iOS. Please give an example of a good pattern for solving this issue. Also an argument why this solution is awesome.

    Read the article

  • Apache Commons PropertiesConfiguration escapes characters on Save [migrated]

    - by Anuvrat
    I am using the commons-configuration from apache commons library. I have a properties file which has properties like: blog_loc=http://my.blog.com blog_name="my blog name" I open the properties file, change the blog_name property and save the file. The following are the lines of code I use: PropertiesConfiguration propertyFile = new PropertiesConfiguration(propertyFileName); propertyFile.setProperty(blog_name, "blog name"); propertyFile.save(propertyFileName + ".out"); Unfortunately, in the output file certain characters get escaped as follows: blog_loc=http:\/\/my.blog.com blog_name=\"blog name\" Is there any way of preventing escaping of the above characters?

    Read the article

  • Looking for some OO design advice

    - by Andrew Stephens
    I'm developing an app that will be used to open and close valves in an industrial environment, and was thinking of something simple like this:- public static void ValveController { public static void OpenValve(string valveName) { // Implementation to open the valve } public static void CloseValve(string valveName) { // Implementation to close the valve } } (The implementation would write a few bytes of data to the serial port to control the valve - an "address" derived from the valve name, and either a "1" or "0" to open or close the valve). Another dev asked whether we should instead create a separate class for each physical valve, of which there are dozens. I agree it would be nicer to write code like PlasmaValve.Open() rather than ValveController.OpenValve("plasma"), but is this overkill? Also, I was wondering how best to tackle the design with a couple of hypothetical future requirements in mind:- We are asked to support a new type of valve requiring different values to open and close it (not 0 and 1). We are asked to support a valve that can be set to any position from 0-100, rather than simply "open" or "closed". Normally I would use inheritance for this kind of thing, but I've recently started to get my head around "composition over inheritance" and wonder if there is a slicker solution to be had using composition?

    Read the article

  • Test case as a function or test case as a class

    - by GodMan
    I am having a design problem in test automation:- Requirements - Need to test different servers (using unix console and not GUI) through automation framework. Tests which I'm going to run - Unit, System, Integration Question: While designing a test case, I am thinking that a Test Case should be a part of a test suite (test suite is a class), just as we have in Python's pyunit framework. But, should we keep test cases as functions for a scalable automation framework or should be keep test cases as separate classes(each having their own setup, run and teardown methods) ? From automation perspective, Is the idea of having a test case as a class more scalable, maintainable or as a function?

    Read the article

  • What do you do when you encounter an idiotic interview question?

    - by Senthil
    I was interviewing with a "too proud of my java skills"-looking person. He asked me "What is your knowledge on Java IO classes.. say.. hash maps?" He asked me to write a piece of java code on paper - instantiate a class and call one of the instance's methods. When I was done, he said my program wouldn't run. After 5 minutes of serious thinking, I gave up and asked why. He said I didn't write a main function so it wouldn't run. ON PAPER. [I am too furious to continue with the stupidity...] Believe me it wasn't trick questions or a psychic or anger management evaluation thing. I can tell from his face, he was proud of these questions. That "developer" was supposed to "judge" the candidates. I can think of several things: Hit him with a chair (which I so desperately wanted to) and walk out. Simply walk out. Ridicule him saying he didn't make sense. Politely let him know that he didn't make sense and go on to try and answer the questions. Don't tell him anything, but simply go on to try and answer the questions. So far, I have tried just 4 and 5. It hasn't helped. Unfortunately many candidates seem to do the same and remain polite but this lets these kind of "developers" just keep ascending up the corporate ladder, gradually getting the capacity to pi** off more and more people. How do you handle these interviewers without bursting your veins? What is the proper way to handle this, yet maintain your reputation if other potential employers were to ever get to know what happened here? Is there anything you can do or should you even try to fix this? P.S. Let me admit that my anger has been amplified many times by the facts: He was smiling like you wouldn't believe. I got so many (20 or so) calls from that company the day before, asking me to come to the interview, that I couldn't do any work that day. I wasted a paid day off.

    Read the article

  • Modular enterprise architecture using MVC and Orchard CMS

    - by MrJD
    I'm making a large scale MVC application using Orchard. And I'm going to be separating my logic into modules. I'm also trying to heavily decouple the application for maximum extensibility and testability. I have a rudimentary understanding of IoC, Repository Pattern, Unit of Work pattern and Service Layer pattern. I've made myself a diagram. I'm wondering if it is correct and if there is anything I have missed regarding an extensible application. Note that each module is a separate project. Update So I have many UI modules that use the db module, that's why they've been split up. There are other services the UI modules will use. The UI modules have been split up because they will be made over time, independent of each other.

    Read the article

  • Should I use Ruby version 1.8.7 or 1.9.2 to start developing Rails apps?

    - by BeachRunnerJoe
    Hello. I'm diving into RoR and I see that the current version of Rails (3.0.5) works with both 1.8.7 and 1.9.2. Currently, I have both versions of Ruby installed using RVM, but I'm wondering which version I should be using as I dive into Rails and start developing apps. I suppose I'd prefer to use the newest version (1.9.2), but I don't know the technologies well enough to know pros/cons of using either. Thanks so much!

    Read the article

  • Versioning millions of files with distributed SCM

    - by C. Lawrence Wenham
    I'm looking into the feasibility of using off-the-shelf distributed SCMs such as Git or Mercurial to manage millions of XML files. Each file would be a commercial transaction, such as a purchase order, that would be updated perhaps 10 times during the lifecycle of the transaction until it is "done" and changes no more. And by "manage", I mean that the SCM would be used to not just version the files, but also to replicate them to other machines for redundancy and transfer of IP. Lets suppose, for the sake of example, that a goal is to provide good performance if it was handling the volume of orders that Amazon.com claimed to have at its peak in December 2010: about 150,000 orders per minute. We're expecting the system to be distributed over many servers in order to get reasonable performance. We're also planning to use solid-state drives exclusively. There is a reason why we don't want to use an RDBMS for primary storage, but it's a bit beyond the scope of this question. Does anyone have first-hand experience with the performance of distributed SCMs under such a load, and what strategies were used? Open-source preferred, since the final product is to be FOSS, too.

    Read the article

  • how do you manage application performance reviews

    - by CoolBeans
    I have been trying to figure out ways to effectively do performance reviews before an install happens for all releases done by our team. Do you usually make this a part of code review process or do you handle it as a separate review task? FYI - we do not have a dedicated performance testing team. It is up to the developers to make sure the app performs well. The apps I am referring to are web applications.

    Read the article

  • JSP Include: one large bean or bean for each include

    - by shylynx
    I want to refactor a webapp that consists of very distorted JSPs and servlets. Because we can't switch to a web framework easily we have to keep JSPs and Servlets, and now we are in doubt how to include pages into another and how to setup the use:bean-directives effectively. At the first step we want to decouple the code for the core-actions and the bean-creation into servlets. The servlets should forward to their corresponding pages, which should use the bean. The problem here is, that each jsp consists of different sub- and sub-sub-jsp that are included into another. Here is a shortend extract (because reality is more complex): head header top navigation actionspanel main header actionspanel foot footer Moreover each jsp (also the header and footer) use dynamic data. For example title and actionspanel can change on each page-reload or do have links and labels that depend on the processing by the preceding servlet. I know that jsp-include-directives should only be used for static content und should be avoided for dynamic content. But here we have very large pages, that consist of many parts. Now the core questions: Should I use one big bean for each page, so that each bean holds also data for header and footer beside its core data, so that each subsequent included jsp uses the same bean-directive? For example: DirectoryJSP <- DirectoryBean CompareJSP <- CompareBean Or should I use one bean for each jsp, so that each bean only holds the data for one jsp and its own purpose. For example: DirectoryJSP <- DirectoryBean HeaderJSP <- HeaderBean FooterJSP <- FooterBean CompareJSP <- CompareBean HeaderJSP <- HeaderBean FooterJSP <- FooterBean In the second case: should the subsequent beans be a member of the corresponding parent bean, so that only the parent bean is attached as attribute to the request? Or should each bean attached to the request?

    Read the article

  • IL and case-sensitivity

    - by Ali .NET
    Quoted from A Brief Introduction To IL code, CLR, CTS, CLS and JIT In .NET CLS stands for Common Language Specifications. It is a subset of CTS. CLS is a set of rules or guidelines which if followed ensures that code written in one .NET language can be used by another .NET language. For example one rule is that we cannot have member functions with same name with case difference only i.e we should not have add() and Add(). This may work in C# because it is case-sensitive but if try to use that C# code in VB.NET, it is not possible because VB.NET is not case-sensitive. Based on above text I want to confirm two points here: Does the case-sensitivity of IL is a condition for member functions only, and not for member properties? Is it true that C# wouldn't be inter-operable with VB.NET if it didn't take care of the case sensitivity?

    Read the article

  • Do immutable objects and DDD go together?

    - by SnOrfus
    Consider a system that uses DDD (as well: any system that uses an ORM). The point of any system realistically, in nearly every use case, will be to manipulate those domain objects. Otherwise there's no real effect or purpose. Modifying an immutable object will cause it to generate a new record after the object is persisted which creates massive bloat in the datasource (unless you delete previous records after modifications). I can see the benefit of using immutable objects, but in this sense, I can't ever see a useful case for using immutable objects. Is this wrong?

    Read the article

  • Handling changes to data types and entries in a database migration

    - by jandjorgensen
    I'm fully redesigning a site that indexes a number of articles with basic search functionality. The previous site was written about a decade ago, and I'm salvaging about 30,000 entries with data stored in less-than-ideal formats. While I'm moving from MSSQL to MySQL, I don't need to make any "live" changes, so this is not a production-level migration issue so much as a redesign. For instance, dates are stored the same as tags/subjects about the articles, but in strings as "YYYYMMDDd" (the lowercase d stands for "date" in the string). Essentially, before or after I move from the previous database format to a new one, I'm going to need to do a lot of replacement of individual entries. While I understand how to do operations with regular expressions in non-database issues, my database experience isn't robust enough to know the best way to handle this. What is the best (or standard) way to handle major changes like this? Is there an SQL operation I should be looking into? Please let me know if the problem isn't clear--I'm not entirely sure what kind of answer I'm looking for.

    Read the article

  • Data Aggregation of CSV files java

    - by royB
    I have k csv files (5 csv files for example), each file has m fields which produce a key and n values. I need to produce a single csv file with aggregated data. I'm looking for the most efficient solution for this problem, speed mainly. I don't think by the way that we will have memory issues. Also I would like to know if hashing is really a good solution because we will have to use 64 bit hashing solution to reduce the chance for a collision to less than 1% (we are having around 30000000 rows per aggregation). For example file 1: f1,f2,f3,v1,v2,v3,v4 a1,b1,c1,50,60,70,80 a3,b2,c4,60,60,80,90 file 2: f1,f2,f3,v1,v2,v3,v4 a1,b1,c1,30,50,90,40 a3,b2,c4,30,70,50,90 result: f1,f2,f3,v1,v2,v3,v4 a1,b1,c1,80,110,160,120 a3,b2,c4,90,130,130,180 algorithm that we thought until now: hashing (using concurentHashTable) merge sorting the files DB: using mysql or hadoop or redis. The solution needs to be able to handle Huge amount of data (each file more than two million rows) a better example: file 1 country,city,peopleNum england,london,1000000 england,coventry,500000 file 2: country,city,peopleNum england,london,500000 england,coventry,500000 england,manchester,500000 merged file: country,city,peopleNum england,london,1500000 england,coventry,1000000 england,manchester,500000 The key is: country,city. This is just an example, my real key is of size 6 and the data columns are of size 8 - total of 14 columns. We would like that the solution will be the fastest in regard of data processing.

    Read the article

  • Abstract Data Type and Data Structure

    - by mark075
    It's quite difficult for me to understand these terms. I searched on google and read a little on Wikipedia but I'm still not sure. I've determined so far that: Abstract Data Type is a definition of new type, describes its properties and operations. Data Structure is an implementation of ADT. Many ADT can be implemented as the same Data Structure. If I think right, array as ADT means a collection of elements and as Data Structure, how it's stored in a memory. Stack is ADT with push, pop operations, but can we say about stack data structure if I mean I used stack implemented as an array in my algorithm? And why heap isn't ADT? It can be implemented as tree or an array.

    Read the article

  • Is there a LOGO interpreter that actually has a turtle?

    - by Tim Post
    This is not a repeat of the now infamous "How do I move the turtle in LOGO?" Recently, I had the following conversation with my five year old daughter: Daughter: Daddy, do you write programs? Me: Yes! Daughter: Daddy, what's a program? Me: A program is a set of instructions that a computer follows. Daughter: Daddy, can I write a program too? Me: Sure! This got me scrambling to think of a very basic language that a five year old could get some satisfaction from mastering rather quickly. I'm ashamed to admit that the first thing that came to mind was this: 10 INPUT "Tell me a secret" A$ 20 PRINT "Wow really? :" A$ 30 GOTO 10 That isn't going to hold a five year old's attention for very long and it requires too much of a lecture. However, moving a turtle around and drawing neat pictures might just work. Sadly, my search for a LOGO interpreter yielded noting but ad ridden sites, flight simulators and a whole bunch of other stuff that I really don't want. I'm hoping to find a cross platform (Java / Python) LOGO interpreter (dare I call it simulator?) with the following features: Can save / replay commands (stored programs) Has an actual turtle Sound effects are a plus Have you stumbled across something like this, if so, can you provide a link? I hate to ask a 'shopping' sort of question, but it seemed much better than "Is LOGO appropriate for a five year old?"

    Read the article

  • Exception while running an EJB program [closed]

    - by rajesh
    I'm a newbie to JEE. I'm trying a sample EJB3 program given in this website. while trying to run the client program, I get an exception like this [JBossManagedConnectionPool] Throwable while attempting to get a new connection: null org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (org.jboss.resource.JBossResourceException: Failed to register driver for: com.mysql.jdbc.Driver; - nested throwable: (java.lang.ClassNotFoundException: com.mysql.jdbc.Driver from BaseClassLoader@4c19dd{VFSClassLoaderPolicy@35fd58{name=vfszip:/home/rajesh/workspace/jboss-5.1.0.GA/server/default/deploy/FirstJPAproject.jar/ domain=ClassLoaderDomain@17380fc{name=DefaultDomain parentPolicy=BEFORE parent=org.jboss.bootstrap.NoAnnotationURLClassLoader@76cbf7} roots=[MemoryContextHandler@9160338[path= context=vfsmemory://3j001-rho3wm-h8v3wfs4-1-h8v5pkwn-9u real=vfsmemory://3j001-rho3wm-h8v3wfs4-1-h8v5pkwn-9u], DelegatingHandler@25335794[path=FirstJPAproject.jar context=file:/home/rajesh/workspace/jboss-5.1.0.GA/server/default/deploy/ real=file:/home/rajesh/workspace/jboss-5.1.0.GA/server/default/deploy/FirstJPAproject.jar] I'm using Jboss5.1.0 and ejb 3.0 Please help me to get rid of this.

    Read the article

  • Personal knowledge base [closed]

    - by AlexLocust
    Possible Duplicate: How do you manage your knowledge base? Hello. Now I am using easy writing pad for scratches while doing some researches, solving troubles or doing workarounds. But.. you now, it's really difficult to remember all details of founded solution and it's alternatives after few months. And writing pad is not wery useful. Usually writing pad doesn't contains half of needed inforation: links founded in internet, output of some test commands and etc. Now I'am looking for a tool for storing information about my researches and it's results. Basic reqirements: ability to store files; ability to store formatted text (kind of HTML will be nice) with hyperlinks and code snippets; tags on notes; easy to use. Now I'am thinking about some kind of file-system organized storage, but I think it will be inconvenient. Another thinks is local wiki or blog. So, my question is: How do you organize you knowlege base? What tools do you use, and what "pros and cons".

    Read the article

< Previous Page | 171 172 173 174 175 176 177 178 179 180 181 182  | Next Page >