Search Results

Search found 14545 results on 582 pages for 'design patterns'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 219/582 | < Previous Page | 215 216 217 218 219 220 221 222 223 224 225 226  | Next Page >

  • Anticipate factorial overflow

    - by Flavius
    Hi I'm wondering how I could anticipate that the next iteration will generate an integer overflow while calculating the factorial F. Let's say that at each iteration I have an int I and the maximum value is MAX_INT. It sounds like a homework, I know. It's not. It's just me asking myself "stupid" questions.

    Read the article

  • How do I indicate success and failure with colour?

    - by Steve McLeod
    I need to make a Java component that turns the background a certain colour when a process passed, and another colour when the process failed. My first thought was: green for success, red for failure. But then I read that 10% of males can't differentiate between these two colours. What would be a better combination of colours? (For the nitpickers: yes, I know that colour alone doesn't suffice, that text, shape, and noise can also be used. Nevertheless I am asking about the appropriate use of colour.)

    Read the article

  • Access variables from a number of sources

    - by mac_55
    I'm creating my first game, and I've currently set up a 'GameState' class, to store player health etc. inside. This class is currently instantiated from the AppDelegate as I need to access it from all over my game. This is fine. For each class I'm working in, I can access the app delegate, and then find the GameState object... however, it seems very messy. I'm tempted to find a way (I'm still a newbie) to define the GameState instance as being some sort of global variable so that I can access it from all over with ease... but my little bit of reading on variable scope makes me uneasy about doing this, even if I knew how. Any ideas of the best way to define and access this class? It'll be used for everything from player health, to items they've found, any personalisation etc. Thanks!

    Read the article

  • Advantage of using a static member function instead of an equivalent non-static member function?

    - by jonathanasdf
    I was wondering whether there's any advantages to using a static member function when there is a non-static equivalent. Will it result in faster execution (because of not having to care about all of the member variables), or maybe less use of memory (because of not being included in all instances)? Basically, the function I'm looking at is an utility function to rotate an integer array representing pixel colours an arbitrary number of degrees around an arbitrary centre point. It is placed in my abstract Bullet base class, since only the bullets will be using it and I didn't want the overhead of calling it in some utility class. It's a bit too long and used in every single derived bullet class, making it probably not a good idea to inline. How would you suggest I define this function? As a static member function of Bullet, of a non-static member function of Bullet, or maybe not as a member of Bullet but defined outside of the class in Bullet.h? What are the advantages and disadvantages of each?

    Read the article

  • Why Use PHP OOP over Basic Functions and When?

    - by Codex73
    There are some posts about this matter, but I didn't clearly get when to use Object Oriented coding and when to use programmatic functions in an include. Somebody also mentioned to me that OOP is very heavy to run, and makes more workload. Is this right? Lets say I have a big file with 50 functions, why will I want to call these in a class? and not by function_name(). Should I switch and create object which holds all of my functions? What will be the advantage or specific difference? What benefits does it bring to code OOP in php ? Modularity?

    Read the article

  • why is java.lang.Throwable a class?

    - by mdma
    In java adjectives ending in -able are interfaces Serializable, Comparable etc... So why is Throwable a class? Wouldn't exception handling be easier if Throwable were an interface? Obviously, changing it now is out the question. But could it be made abstract? Wouldn't that avoid the bad practice of throw new Throwable();

    Read the article

  • How do I call exec in psake to an executable with a variable path?

    - by Josh Kodroff
    I can't seem to call this executable correctly in my psake deploy script. If I do this: exec { "$ArchiverOutputDir\NServiceBus.Host.exe /install" } It simply outputs this (and is clearly not calling the executable - just outputting the value of that expression): c:\ReloDotNet2_ServiceEndpoints\Archiver\NServiceBus.Host.exe /install But if I do this: exec { c:\ReloDotNet2_ServiceEndpoints\Archiver\NServiceBus.Host.exe /install } I get the expected output from the executable. How do I correctly call an executable with a variable in the path to the executable in psake? If this is actually a PowerShell issue, please feel free to correct the question to reflect that insight. I

    Read the article

  • Business Objects - Containers or functional?

    - by Walter
    Where I work, we've gone back and forth on this subject a number of times and are looking for a sanity check. Here's the question: Should Business Objects be data containers (more like DTOs) or should they also contain logic that can perform some functionality on that object. Example - Take a customer object, it probably contains some common properties (Name, Id, etc), should that customer object also include functions (Save, Calc, etc.)? One line of reasoning says separate the object from the functionality (single responsibility principal) and put the functionality in a Business Logic layer or object. The other line of reasoning says, no, if I have a customer object I just want to call Customer.Save and be done with it. Why do I need to know about how to save a customer if I'm consuming the object? Our last two projects have had the objects separated from the functionality, but the debate has been raised again on a new project. Which makes more sense? EDIT These results are very similar to our debates. One vote to one side or another completely changes the direction. Does anyone else want to add their 2 cents? EDIT Eventhough the answer sampling is small, it appears that the majority believe that functionality in a business object is acceptable as long as it is simple but persistence is best placed in a separate class/layer. We'll give this a try. Thanks for everyone's input...

    Read the article

  • Sequence numbers best practice

    - by Abdullah Jibaly
    What's the best practice or well known methods to implement sequence numbers for business entities such as invoices, purchase orders, job numbers, etc? I want to be able to save the latest value in the database and be able to set it programatically. Is it OK to use a table for this purpose that has a SEQUENCE_NAME, SEQUENCE_NUMBER tuple? I know some databases have a first class sequence type but others (eg, MySQL) do not so it's not something I want to rely on. If a table is used to hold these sequences what is the right way to get and increment them in a synchronized fashion to ensure no data inconsistencies arise?

    Read the article

  • Branchless memory manager?

    - by Richard Fabian
    Anyone thought about how to write a memory manager (in C++) that is completely branch free? I've written a pool, a stack, a queue, and a linked list (allocating from the pool), but I am wondering how plausible it is to write a branch free general memory manager. This is all to help make a really reusable framework for doing solid concurrent, in-order CPU, and cache friendly development. Edit: by branchless I mean without doing direct or indirect function calls, and without using ifs. I've been thinking that I can probably implement something that first changes the requested size to zero for false calls, but haven't really got much more than that. I feel that it's not impossible, but the other aspect of this exercise is then profiling it on said "unfriendly" processors to see if it's worth trying as hard as this to avoid branching.

    Read the article

  • How do I dynamically instantiate a class in javascript?

    - by Adam
    I'm starting out with classes in Javascript and have hit a wall. I've looked all over for a tutorial that goes a little further than simply how to construct a class (usually Animal) then extend the class and have a Method do something (Dog alert('Bark');). I have created a class that I want a user to be able to instantiate (is that the right word)? For example the first stage in my program is for the user to give the class a name, and then start to populate the various variables in the class. When they've done that they may do it again many times. So if: var className = new MyObject(); How do I dynamically create the name of the new object className and then refer to it later in the code?

    Read the article

  • Validating class and superclass on RoR

    - by Luís Guilherme
    In ruby, you have an attribute called "type" which is the class of the object. Rails stores this at the database in a column called type. So, if I have several blog "types", I can do something like this def create @blog = Blog.new(params[:blog]) @blog[:type] = params[:blog][:type] # ... end If I add someone like this, and then load it, and ask its class (for instance, at the console), I have the right class name answered back. However, when I save it afterwards, rails will run only the superclass validators, not the ones I defined in the subclass. How should I make rails run the subclass validators?

    Read the article

  • What are some best practises and "rules of thumb" for creating database indexes?

    - by Ash
    I have an app, which cycles through a huge number of records in a database table and performs a number of SQL and .Net operations on records within that database (currently I am using Castle.ActiveRecord on PostgreSQL). I added some basic btree indexes on a couple of the feilds, and as you would expect, the peformance of the SQL operations increased substantially. Wanting to make the most of dbms performance I want to make some better educated choices about what I should index on all my projects. I understand that there is a detrement to performance when doing inserts (as the database needs to update the index, as well as the data), but what suggestions and best practices should I consider with creating database indexes? How do I best select the feilds/combination of fields for a set of database indexes (rules of thumb)? Also, how do I best select which index to use as a clustered index? And when it comes to the access method, under what conditions should I use a btree over a hash or a gist or a gin (what are they anyway?).

    Read the article

  • Is there a Delphi dropdown notification component?

    - by Mason Wheeler
    You know how in Firefox, if something happens that requires your attention but isn't immediately urgent enough to require a modal dialog, it will drop down a little strip at the top of the tab with a question on it? I'd like to be able to put functionality like that in a Delphi app, but I don't know if there's a component for that. Does anyone know of one?

    Read the article

  • Writing fortran robust and "modern" code

    - by Blklight
    In some scientific environments, you often cannot go without FORTRAN as most of the developers only know that idiom, and there is lot of legacy code and related experience. And frankly, there are not many other cross-platform options for high performance programming ( C++ would do the task, but the syntax, zero-starting arrays, and pointers are too much for most engineers ;-) ). I'm a C++ guy but I'm stuck with some F90 projects. So, let's assume a new project must use FORTRAN (F90), but I want to build the most modern software architecture out of it. while being compatible with most "recent" compilers (intel ifort, but also including sun/HP/IBM own compilers) So I'm thinking of imposing: global variable forbidden, no gotos, no jump labels, "implicit none", etc. "object-oriented programming" (modules with datatypes + related subroutines) modular/reusable functions, well documented, reusable libraries assertions/preconditions/invariants (implemented using preprocessor statements) unit tests for all (most) subroutines and "objects" an intense "debug mode" (#ifdef DEBUG) with more checks and all possible Intel compiler checks possible (array bounds, subroutine interfaces, etc.) uniform and enforced legible coding style, using code processing tools C stubs/wrappers for libpthread, libDL (and eventually GPU kernels, etc.) C/C++ implementation of utility functions (strings, file operations, sockets, memory alloc/dealloc reference counting for debug mode, etc.) ( This may all seem "evident" modern programming assumptions, but in a legacy fortran world, most of these are big changes in the typical programmer workflow ) The goal with all that is to have trustworthy, maintainable and modular code. Whereas, in typical fortran, modularity is often not a primary goal, and code is trustworthy only if the original developer was very clever, and the code was not changed since then ! (i'm a bit joking here, but not much) I searched around for references about object-oriented fortran, programming-by-contract (assertions/preconditions/etc.), and found only ugly and outdated documents, syntaxes and papers done by people with no large-scale project involvement, and dead projects. Any good URL, advice, reference paper/books on the subject?

    Read the article

  • How strict to be when using Qt framework?

    - by toffeehoops
    I'm building a Qt application that needs to use libssh, a SSH client library. libssh (understandably) performs its own network connections, however Qt has its own infrastructure for network connections (QTcpSocket etc). Should I worry about these differences? Should I be trying to make libssh make network connections via QTcpSocket... Or if it works fine on the platforms I'm targeting, is that good enough?

    Read the article

  • Usability: call for action

    - by Shyam
    I am designing a page, with tiny portlets. Now, I personally like my actions on the right side, yet I wonder if there are methodologies that are targeted about usability. After all, most applications are aimed at the user. What about yourself? Do you prefer information to be on top, on the left or on the right? I've you need to take some sort of action, do you prefer buttons on the left? References to good books and webpages are very welcome!

    Read the article

  • add schema to path in postgresql

    - by veilig
    I'm the process of moving applications over from all in the public schema to each having their own schema. for each application, I have a small script that will create the schema and then create the tables,functions,etc... to that schema. Is there anyway to automatically add a newly created schema to the search_path? Currently, the only way I see is to find the users current path SHOW search_path; and then add the new schema to it SET search_path to xxx,yyy,zzz; I would like some way to just say, append schema zzz to the users_search path. is this possible?

    Read the article

  • When should I use Dependency Injection and when utility methods?

    - by Roman
    I have a Java EE project with Spring IoC container. I've just found in Utils class static method sendMail(long list of params). I don't know why but I feel that it would look better if we had separate class (Spring bean with singleton scope) which will be responsible for sending email. But I can't find any arguments which can prove my position. So, are there any pros (or cons) in using DI in this (rather general) situation?

    Read the article

  • Need help to create database schema for wholesale online tee store

    - by techiepark
    Hi, I'm currently working on wholesale online t-shirt shop. I have done this for fixed quantity and price, and its working fine. Now i need to do this for variable quantity and price. Here is the reference link, like what i have to do. Basic tables i have created are - CREATE TABLE attribute ( attribute_id int(11) NOT NULL auto_increment, name varchar(100) NOT NULL, PRIMARY KEY (attribute_id) ); CREATE TABLE attribute_value ( attribute_value_id int(11) NOT NULL auto_increment, attribute_id int(11) NOT NULL, value varchar(100) NOT NULL, PRIMARY KEY (attribute_value_id), KEY idx_attribute_value_attribute_id (attribute_id) ); CREATE TABLE product ( product_id int(11) NOT NULL auto_increment, name varchar(100) NOT NULL, description varchar(1000) NOT NULL, price decimal(10,2) NOT NULL, image varchar(150) default NULL, thumbnail varchar(150) default NULL, PRIMARY KEY (product_id), FULLTEXT KEY idx_ft_product_name_description (name,description) ); CREATE TABLE product_attribute ( product_id int(11) NOT NULL, attribute_value_id int(11) NOT NULL, PRIMARY KEY (product_id,attribute_value_id) ); I'm not getting how to store the price based on variable quantity. Please help me to create product and its related tables. my requirement is same as above reference link.

    Read the article

  • How does this code break the Law of Demeter?

    - by Dave Jarvis
    The following code breaks the Law of Demeter: public class Student extends Person { private Grades grades; public Student() { } /** Must never return null; throw an appropriately named exception, instead. */ private synchronized Grades getGrades() throws GradesException { if( this.grades == null ) { this.grades = createGrades(); } return this.grades; } /** Create a new instance of grades for this student. */ protected Grades createGrades() throws GradesException { // Reads the grades from the database, if needed. // return new Grades(); } /** Answers if this student was graded by a teacher with the given name. */ public boolean isTeacher( int year, String name ) throws GradesException, TeacherException { // The method only knows about Teacher instances. // return getTeacher( year ).nameEquals( name ); } private Grades getGradesForYear( int year ) throws GradesException { // The method only knows about Grades instances. // return getGrades().getForYear( year ); } private Teacher getTeacher( int year ) throws GradesException, TeacherException { // This method knows about Grades and Teacher instances. A mistake? // return getGradesForYear( year ).getTeacher(); } } public class Teacher extends Person { public Teacher() { } /** * This method will take into consideration first name, * last name, middle initial, case sensitivity, and * eventually it could answer true to wild cards and * regular expressions. */ public boolean nameEquals( String name ) { return getName().equalsIgnoreCase( name ); } /** Never returns null. */ private synchronized String getName() { if( this.name == null ) { this.name == ""; } return this.name; } } Questions How is the LoD broken? Where is the code breaking the LoD? How should the code be written to uphold the LoD?

    Read the article

  • MYSQL Event to update another database table

    - by Lee
    Hey All, I have just taken over a project for a client and the database schema is in a total mess. I would like to rename a load of fields make it a relationship database. But doing this will be a painstaking process as they have an API running of it also. So the idea would be to create a new database and start re-writing the code to use this instead. But I need a way to keep these tables in sync during this process. Would you agree that I should use MYSQL EVENT's to keep updating the new table on Inserts / updates & deletes?? Or can you suggest a better way?? Hope you can advise !! thanks for any input I get

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 215 216 217 218 219 220 221 222 223 224 225 226  | Next Page >