Search Results

Search found 14074 results on 563 pages for 'programmers'.

Page 248/563 | < Previous Page | 244 245 246 247 248 249 250 251 252 253 254 255  | Next Page >

  • How to start a high school Java/Android development club for 13-17 year olds

    - by PaulHurleyuk
    My wife is a high school maths teacher, and is considering starting a programming club for 13-17 years olds who show an interest. Their interest seems to be around Apps and Android which I have little experience of. The kids would be (presumably) interested in programming, and have a fairly high level of computing knowledge. We would provide them with resources and some knowledge, but hopefully a lot would be self guided. I'm hoping stack overflow'ers can provide some tips or starting points. Specific things I think I'll need are; A development Environment; Currently I'm looking towards Java and Android, developed in Eclipse, probably installed on donated older hardware Some initial direction; There seem to be a plethora or 'start android' tutorials, so some recommendations for good ones are valuable, as are recommended paper books A Target; Some final project they should be shooting for A Route; This is where I'm most stuck, how to lead them through the required Java concepts and learning they would need Some related questions already out there Language+IDE for teaching high school students? Teaching "web design/development" to high-school home-school group. Good sources? How can I bootstrap a software development community at my school?

    Read the article

  • Big Oh notation does not mention constant value

    - by user883561
    I am a programmer and have just started reading Algorithms. I am not completely convinced with the notations namely Bog Oh, Big Omega and Big Theta. The reason is by definition of Big Oh, it states that there should be a function g(x) such that it is always greater than or equal to f(x). Or f(x) <= c.n for all values of n n0. My doubt is the why dont we mention the constant value in the definition? For example. lets say a function 6n+4, we denote it as O(n). but its not true that the definition holds good for all constant value. this holds good only when c = 10 and n = 1. For lesser values of c than 6, the value of n0 increases. So why we do not mention the constant value as a part of the definition.

    Read the article

  • Where to store front-end data for "object calculator"

    - by Justin Grahn
    I recently have completed a language library that acts as a giant filter for food items, and flows a bit like this :Products -> Recipes -> MenuItems -> Meals and finally, upon submission, creates an Order. I have also completed a database structure that stores all the pertinent information to each class, and seems to fit my needs. The issue I'm having is linking the two. I imagined all of the information being local to each instance of the product, where there exists one backend user who edits and manipulates data, and multiple front end users who select their Meal(s) to create an Order. Ideally, all of the front end users would have all of this information stored locally within the library, and would update the library on startup from a database. How should I go about storing the data so that I can load it into the library every time the user opens the application? Do I package a database onboard and just load and populate every time? The only method I can currently conceive of doing this, even if I only have 500 possible Product objects, would require me to foreach the list for every Product that I need to match to a Recipe and so on and so forth every time I relaunch the program, which seems like a lot of wasteful loading. Here is a general flow of my architecture: Products: public class Product : IPortionable { public Product(string n, uint pNumber = 0) { name = n; productNumber = pNumber; } public string name { get; set; } public uint productNumber { get; set; } } Recipes: public Recipe(string n, decimal yieldAmt, Volume.Unit unit) { name = n; yield = new Volume(yieldAmt, unit); yield.ConvertUnit(); } /// <summary> /// Creates a new ingredient object /// </summary> /// <param name="n">Name</param> /// <param name="yieldAmt">Recipe Yield</param> /// <param name="unit">Unit of Yield</param> public Recipe(string n, decimal yieldAmt, Weight.Unit unit) { name = n; yield = new Weight(yieldAmt, unit); } public Recipe(Recipe r) { name = r.name; yield = r.yield; ingredients = r.ingredients; } public string name { get; set; } public IMeasure yield; public Dictionary<IPortionable, IMeasure> ingredients = new Dictionary<IPortionable,IMeasure>(); MenuItems: public abstract class MenuItem : IScalable { public static string title = null; public string name { get; set; } public decimal maxPortionSize { get; set; } public decimal minPortionSize { get; set; } public Dictionary<IPortionable, IMeasure> ingredients = new Dictionary<IPortionable, IMeasure>(); and Meal: public class Meal { public Meal(int guests) { guestCount = guests; } public int guestCount { get; private set; } //TODO: Make a new MainCourse class that holds pasta and Entree public Dictionary<string, int> counts = new Dictionary<string, int>(){ {MainCourse.title, 0}, {Side.title , 0}, {Appetizer.title, 0} }; public List<MenuItem> items = new List<MenuItem>(); The Database just stores and links each of these basic names and amounts together usings ID's (RecipeID, ProductID and MenuItemID)

    Read the article

  • Metaphor for task synchronization [closed]

    - by nkint
    I'm looking for a metaphor. A friend of mine taught me to use metaphors from nature, everyday life, math, and use them to design my projects. They can help in creating a better design or better understanding or the problem, and they are cool. Now I'm working on a project with hardware and micro-controllers in C. For convenience, I have decided to use multiple micro-controllers as co-processor units for real-time (the slaves) and a master. This has saved me a lot of headache: I can code the main logic in the master without paying too much attention to super optimizing everything; I don't care if I need some blocking-call; I don't worry about serial communication with the computer. I just send messages to the slaves and they are super fast super in real time. I like my design and it seems to work well. So here are the important concepts that I'm trying capture in the metaphor: hierarchy of processing Not using one big brain but rather several small, distributed brain units using distributed power or resources I'm looking for a good metaphor for this concept of having one unit synchronize the work of all the others. Preferably, the metaphor would come from nature, biology, or zoology.

    Read the article

  • What layer to introduce human readable error messages?

    - by MrLane
    One of the things that I have never been happy with on any project I have worked on over the years and have really not been able to resolve myself is exactly at what tier in an application should human readable error information be retrieved for display to a user. A common approach that has worked well has been to return strongly typed/concrete "result objects" from the methods on the public surface of the business tier/API. A method on the interface may be: public ClearUserAccountsResult ClearUserAccounts(ClearUserAccountsParam param); And the result class implementation: public class ClearUserAccountsResult : IResult { public readonly List<Account> ClearedAccounts{get; set;} public readonly bool Success {get; set;} // Implements IResult public readonly string Message{get; set;} // Implements IResult, human readable // Constructor implemented here to set readonly properties... } This works great when the API needs to be exposed over WCF as the result object can be serialized. Again this is only done on the public surface of the API/business tier. The error message can also be looked up from the database, which means it can be changed and localized. However, it has always been suspect to me, this idea of returning human readable information from the business tier like this, partly because what constitutes the public surface of the API may change over time...and it may be the case that the API will need to be reused by other API components in the future that do not need the human readable string messages (and looking them up from a database would be an expensive waste). I am thinking a better approach is to keep the business objects free from such result objects and keep them simple and then retrieve human readable error strings somewhere closer to the UI layer or only in the UI itself, but I have two problems here: 1) The UI may be a remote client (Winforms/WPF/Silverlight) or an ASP.NET web application hosted on another server. In these cases the UI will have to fetch the error strings from the server. 2) Often there are multiple legitimate modes of failure. If the business tier becomes so vague and generic in the way it returns errors there may not be enough information exposed publicly to tell what the error actually was: i.e: if a method has 3 modes of legitimate failure but returns a boolean to indicate failure, you cannot work out what the appropriate message to display to the user should be. I have thought about using failure enums as a substitute, they can indicate a specific error that can be tested for and coded against. This is sometimes useful within the business tier itself as a way of passing via method returns the specifics of a failure rather than just a boolean, but it is not so good for serialization scenarios. Is there a well worn pattern for this? What do people think? Thanks.

    Read the article

  • Code structure for multiple applications with a common core

    - by Azrael Seraphin
    I want to create two applications that will have a lot of common functionality. Basically, one system is a more advanced version of the other system. Let's call them Simple and Advanced. The Advanced system will add to, extend, alter and sometimes replace the functionality of the Simple system. For instance, the Advanced system will add new classes, add properties and methods to existing Simple classes, change the behavior of classes, etc. Initially I was thinking that the Advanced classes simply inherited from the Simple classes but I can see the functionality diverging quite significantly as development progresses, even while maintaining a core base functionality. For instance, the Simple system might have a Project class with a Sponsor property whereas the Advanced system has a list of Project.Sponsors. It seems poor practice to inherit from a class and then hide, alter or throw away significant parts of its features. An alternative is just to run two separate code bases and copy the common code between them but that seems inefficient, archaic and fraught with peril. Surely we have moved beyond the days of "copy-and-paste inheritance". Another way to structure it would be to use partial classes and have three projects: Core which has the common functionality, Simple which extends the Core partial classes for the simple system, and Advanced which also extends the Core partial classes for the advanced system. Plus having three test projects as well for each system. This seems like a cleaner approach. What would be the best way to structure the solution/projects/code to create two versions of a similar system? Let's say I later want to create a third system called Extreme, largely based on the Advanced system. Do I then create an AdvancedCore project which both Advanced and Extreme extend using partial classes? Is there a better way to do this? If it matters, this is likely to be a C#/MVC system but I'd be happy to do this in any language/framework that is suitable.

    Read the article

  • PHP - "tabulate" array - make levels from elements

    - by Moha
    If I have an array like this: Array ( [0] => field_schools [1] => und [2] => 0 [3] => field_school [4] => und [5] => 0 [6] => value ) How can I make an array like this from it? array ( [field_schools] => array ( [und] => array ( [0] => array ( [field_school] => array ( [und] => array ( [0] => array ( [value] => something ) ) ) ) ) ) ) I want to specify the 'value' myself.

    Read the article

  • how do you remember programming related stuff?

    - by dan leadgy
    How do you remember programming related stuff? Did you get the feeling you did encounter the error you have now a few years ago and you could swear you knew the cause but now you forgot it? Did you work with the xsl's string parsing some time ago but now you can't remember exactly which are the string functions altogether from xsl and you have to start from scratch? Or perhaps you forget about some feature from Apache Commons like "filtering a collection by some predicate" that you surely used in the past. So how do you do it? I tried having a blog but when I develop apps, I never find the time to update the blog or write about my experiences. Also, using a wiki is a nice thing but then I found it difficult to keep a clean separation between them since many times I needed to change a blog post to add new information about that topic. This made me think that I actually should have put this topic in the wiki instead of the blog. Do you have any systems that help you remember about your programming experience? What's your setup?

    Read the article

  • JS closures - Passing a function to a child, how should the shared object be accessed

    - by slicedtoad
    I have a design and am wondering what the appropriate way to access variables is. I'll demonstrate with this example since I can't seem to describe it better than the title. Term is an object representing a bunch of time data (a repeating duration of time defined by a bunch of attributes) Term has some print functionality but does not implement the print functions itself, rather they are passed in as anonymous functions by the parent. This would be similar to how shaders can be passed to a renderer rather than defined by the renderer. A container (let's call it Box) has a Schedule object that can understand and use Term objects. Box creates Term objects and passes them to Schedule as required. Box also defines the print functions stored in Term. A print function usually takes an argument and uses it to return a string based on that argument and Term's internal data. Sometime the print function could also use data stored in Schedule, though. I'm calling this data shared. So, the question is, what is the best way to access this shared data. I have a lot of options since JS has closures and I'm not familiar enough to know if I should be using them or avoiding them in this case. Options: Create a local "reference" (term used lightly) to the shared data (data is not a primitive) when defining the print function by accessing the shared data through Schedule from Box. Example: var schedule = function(){ var sched = Schedule(); var t1 = Term( function(x){ // Term.print() return (x + sched.data).format(); }); }; Bind it to Term explicitly. (Pass it in Term's constructor or something). Or bind it in Sched after Box passes it. And then access it as an attribute of Term. Pass it in at the same time x is passed to the print function, (from sched). This is the most familiar way for my but it doesn't feel right given JS's closure ability. Do something weird like bind some context and arguments to print. I'm hoping the correct answer isn't purely subjective. If it is, then I guess the answer is just "do whatever works". But I feel like there are some significant differences between the approaches that could have a large impact when stretched beyond my small example.

    Read the article

  • unix career in programming

    - by mnunna
    I am currently working on a HP-UX platform and my role as a prod support team member involves mostly to write shell scripts. But I want to branch out into core systems programming in unix. A quick search on the internet threw no "unix systems programming jobs" in my area. I'm confused as what to do. I really would like to continue with unix as my core competency, but unix jobs are mostly of sys admin/ prod support type, of which I do not want a part of. Can anyone of you give me an informed advice on the career oppurtinities that await unix professionals?? Any advice would be appreciated.

    Read the article

  • Merge sort. ArrayIndexOutOfBoundsException [migrated]

    - by user94892
    When I execute the program I am getting an error as stated below the program. Please help me figure out the problem.. import java.util.*; class Mergesort { public static void main(String args[]) { Scanner in= new Scanner(System.in); System.out.println("Enter the number of elements"); int n= in.nextInt(); int a[]= new int[n]; System.out.println("Enter the contents"); for(int i=0; i<n; i++) { a[i]=in.nextInt(); } a = mergesort(a,n); for(int i=0; i<n; i++) { System.out.println(a[i]); } } public static int[] mergesort(int[] x, int z) { if(z==1) { return x; } int b[]=new int[z/2]; int c[]=new int[z-z/2]; int i,j,k; for(int p=0;p<z/2; p++) { b[p]= x[p]; c[p]= x[p+z/2]; } c[z-z/2-1]= x[z-1]; b= mergesort(b,z/2); c= mergesort(c,z-z/2); for(i=0,j=0,k=0; k<z; k++) { if(b[i]<=c[j]) { x[k]=b[i]; i++; } else if( b[i]>c[j]) { x[k]=c[j]; j++; } else if(i== z/2) { x[k]= c[j]; j++; } else if(j == z-z/2) { x[k]= b[i]; i++; } } return x; } } Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1 at Mergesort.mergesort(Mergesort.java:41) at Mergesort.mergesort(Mergesort.java:36) at Mergesort.main(Mergesort.java:16)

    Read the article

  • Carrer path as Java developer for non Btech or BCA background graduate [closed]

    - by Piyush Jolly
    My name is Piyush and I'm a graduate in Bsc. multimedia. Now I'm planing to learn JAVA and take it as my carrier and there are few things I'm really worried about:- 1)Does the industry accepts graduates from Non-it background. 2)Because my course was all about 3D Animation nothing like software programing was taught to us and I have been doing programing in c from long time just because i liked it so now i want to purse my carrier as programmer. 3)From where should I learn, which Institute should I refer to who teaches the Java from the basic. 4)What kind of jobs I can expect after the completion of the course. I'm from Delhi. Any help will be much appreciated. Regards Piyush Jolly

    Read the article

  • May I remove ads from feed in my news reader app?

    - by Mahdi Ghiasi
    I'm creating a News Reader app for Tablets and PCs. My app is fetching data from news sources by RSS feed of websites (in the server-side). But some of these sites are showing some advertising banners at the end of each article. Should I remove those banners from the feed? Am I legally/ethically allowed to do this? And what about If I want to put some other ads in my application? (Right at the end of each article) I mean, If I want to have my own advertising service... Update: And what if I use feed for content titles and summaries, but use other thing, like Readability API to show full article, and then put my own ads below content? (Readability gets the HTML page, and gives you a clean page without any ads and such.)

    Read the article

  • How to generate a metamodel for POJOs

    - by Stefan Haberl
    I'm looking for a metamodel generation library for simple Java POJOs. I'm thinking about something along the lines of JPA 2.0's metamodel, which can be used to generate type safe criterias for JPA entities (see this Question on SO for JPA specific implementations). Does something similar exist for general purpose JavaBeans, i.e., POJOS, that are not JPA entities? Specifically, I want to implement Spring MVC's WebDataBinder.setAllowedFields() method in a type safe way in my Spring MVC @Controllers

    Read the article

  • Using public domain source code from JDK in my application

    - by user2941369
    Can I use source code from ThreadPoolExecutor.java taken from JDK 1.7 considering that the following clausule is at the beginning of the ThreadPoolExecutor.java: /* * Written by Doug Lea with assistance from members of JCP JSR-166 * Expert Group and released to the public domain, as explained at * http://creativecommons.org/licenses/publicdomain */ And just before that there is also: /* * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */

    Read the article

  • Community to discuss project ideas

    - by Auxiliary
    Although I already predict the down votes but the question has stuck in my throat for a while now. I think this has happened to many of us. Sometimes we find a great idea for a project and obviously think this is THE GREATEST idea ever but then one of the following things will happen: The project is a small one, so you might actually give it a try and see how it goes. The project is a big one, even a risk, and you just need a good programmer's community that you could just discuss your idea with them and see what they say and even get some help to make it happen. And there's always the possibility of others stealing your idea which is really bad. So could anyone suggest an online community or place or even method of talking about ideas and the ways of developing them? and do you think it's a good thing to tell others about your idea?

    Read the article

  • Right multi object dependance design

    - by kenny
    I need some help with a correct design. I have a class called BufferManager. The push() method of this class reads data from a source and pushes it to a buffer repeatedly until there is no more data left in the source. There are also consumer threads that read data from this buffer, as soon as new data arrives. There is an option to sort the data before it comes to buffer. What I do right now is that BufferManager, instead of pushing data to the buffer, pushes it to another "sorting" buffer and starts a sorting thread. SorterManager class reads the data, sorts it in files and push()es the sorted data into the buffer. There will be a bottleneck (I use merge sort with files) but this is something I can't avoid. This is a bad design, because both BufferManager and SorterManager push data to a buffer (that consumers read from). I think only BufferManager should do it. How can I design it?

    Read the article

  • (PHP vs Python vs Perl) vs Ruby [closed]

    - by Dr.Kameleon
    OK, here's what : I've programmed in over 20 different languages and now, because of a large project I'm currently working on for Mac OS X (in Objective-C/Cocoa), I need to make a final decision on which language to use for my background scripting + plugin functionality. Definitely, one factor that'll ultimately influence my decision is which one I'm most familiar with, which is PHP (one of the ugliest languages around, which I however adore... lol), then Python / Perl (the "proven values"... )... and then Ruby (which, to me, is almost confusing and I've only played with it for some time.) Now, here's my considerations : (As previously mentioned) Being familiar with it (anyway, if X is better in my case, I really don't mind studying it from scratch...) Speed Good interaction with the Shell + ease of integration with my Cocoa application Btw, some of the reasons that made me wonder if Ruby would be a good choice is : The hype around it (although, I still don't get why; but that's probably just me...) My major competitor (we're actually talking about the same type of software here) is using Ruby for its backend scripting almost exclusively (ok, along with some BASH). Isn't Ruby considered slower e.g. than Perl? Why did he choose that? Simply, a matter of personal taste? So... your thoughts?

    Read the article

  • Business case for decentralized version control systems

    - by Keyo
    I searched and couldn't find any business reasons why git/mercurial/bazzr systems are better than centralized systems (subversion, perforce). If you were trying to sell a DVCS to a non-technical person what arguments would you provide for the DVCS increasing profit. I will shortly be pitching git to my manager, it will take some time converting out subversion repositories and some expense in buying smartgit licences.

    Read the article

  • What features are helpful when performing remote debugging / diagnostics?

    - by Pemdas
    Obviously, the easiest way to solve a bug is to be able to reproduce it in-house. However, sometimes that is not practical. For starters, users are often not very good at providing you with useful information. Customer Service: "what seems to be the issue?" User: "It crashed!" To further compound that, sometimes the bug only occurs under certain environmentally conditions that can not be adequately replicated in-house. With that in mind, it is important to build some sort of diagnostic framework into your product. What types of built-in diagnostic tools have you used or seen used? Logging seems to be the predominate method, which makes sense. We have a fairly sophisticated logging frame work in place with different levels of verbosity and the ability to filter on specific modules (actually we can filter down to the granularity of a single file). Error logs are placed strategically to manufacture a pretty good representation of a stack trace when an error occurs. We don't have the luxury of 10 million terabytes of disk space since I work on embedded platforms, so we have two ways of getting them off the system: a serial port and a syslog server. However, an issue we run into sometimes is actually getting the user to turn the logs on. Our current framework often requires some user interaction.

    Read the article

  • Are there non-programming related activities akin to solving programming problems ?

    - by julien
    I'm talking about particular activities, for which you can draw parallels with the specific kind of reasonning needed when solving programming problems. Counter examples are activities that would help in almost any situation, like : take a shower or any other, somewhat passive activities, which are only helpful in triggering this sort of asynchronous problem solving our brain does exercise, because you brain simply works better when you're fit EDIT : It seems this question was quite misunderstood. I wasn't asking about what you can do when stuck on a problem but rather, what kind of activities you have in you spare time that you think help you, more or less directly, solving programing problems.

    Read the article

  • What are the algorithms that are used for working with large data in popular web applications

    - by Moss Farmer
    I am looking for some well known algorithms that can be considered while handling very large amount of data.(Edit- By large amount of data I refer to records in a database excluding blobs). These algorithms if not in totality but in parts may be used in big web applications like Twitter, Last.fm , Amazon ,etc. Specifically, I'm looking for names or links to such algorithms. My primary interest lies in developing a very deep understanding on working with large database records and writing efficient code for working with the same.

    Read the article

  • TBXML parsing issue while the value cannot get in UILabel

    - by Dany
    In my app I'm using TBXML parser where I need to get a value from xml file and print it on the label. This is my xml file in server <gold> <price> <title>22 K Gold</title> </price> <price> <title>24 K Gold</title> </price> </gold> any my Viewcontroller.h looks like #import <UIKit/UIKit.h> #import "TBXML.h" @interface ViewController : UIViewController{ IBOutlet UILabel *lab; IBOutlet UILabel *lab1; TBXML *tbxml; } @end and my Viewcontrooler.m looks like - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. NSData *xmlData = [[NSData alloc]initWithContentsOfURL:[NSURL URLWithString:@"http://www.abcde.com/sample.xml"]]; tbxml = [[TBXML alloc]initWithXMLData:xmlData]; TBXMLElement * root = tbxml.rootXMLElement; if (root) { TBXMLElement * elem_PLANT = [TBXML childElementNamed:@"price" parentElement:root]; while (elem_PLANT !=nil) { TBXMLElement * elem_BOTANICAL = [TBXML childElementNamed:@"title" parentElement:elem_PLANT]; NSString *botanicalName = [TBXML textForElement:elem_BOTANICAL]; lab.text=[NSString stringWithFormat:@"re %@", botanicalName]; elem_PLANT = [TBXML nextSiblingNamed:@"price" searchFromElement:elem_PLANT]; elem_BOTANICAL = [TBXML childElementNamed:@"title" parentElement:elem_PLANT]; botanicalName = [TBXML textForElement:elem_BOTANICAL]; lab1.text=[NSString stringWithFormat:@"re %@", botanicalName]; } } } I'm getting BAD_ACCESS thread. Am I missing anything?

    Read the article

  • Erlang web frameworks survey

    - by Zachary K
    (Inspired by similar question on Haskel) There are several web frameworks for Erlang like Nitrogen, Chicago Boss, and Zotonic, and a few more. In what aspects do they differ from each other? For example: features (e.g. server only, or also client scripting, easy support for different kinds of database) maturity (e.g. stability, documentation quality) scalability (e.g. performance, handy abstraction) main targets Also, what are examples of real-world sites / web apps using these frameworks? EDIT: Starting a bounty in hopes that it will get some conversation going

    Read the article

  • Objected oriented approach to structure inside structure

    - by RishiD
    This is for C++ but should apply to any OO language. Trying to figure out the correct object oriented apporach to do the following (this is what I do in C). struct Container { enum type; union { TypeA a; TypeB b; }; } The type field determines if it TypeA or TypeB object. I am using this to handle responses coming back from a connection, they get parsed and get put into this structure and then based on the message type the appropriate fields get filled in. e.g. struct Container parseResponse(bufferIn, bufferLength); Is there an OO approach for doing this?

    Read the article

< Previous Page | 244 245 246 247 248 249 250 251 252 253 254 255  | Next Page >