Search Results

Search found 3076 results on 124 pages for 'beginner'.

Page 26/124 | < Previous Page | 22 23 24 25 26 27 28 29 30 31 32 33  | Next Page >

  • Haskell simple compilation bug

    - by fmsf
    I'm trying to run this code: let coins = [50, 25, 10, 5, 2,1] let candidate = 11 calculate :: [Int] calculate = [ calculate (x+candidate) | x <- coins, x > candidate] I've read some tutorials, and it worked out ok. I'm trying to solve some small problems to give-me a feel of the language. But I'm stuck at this. test.hs:3:0: parse error (possibly incorrect indentation) Can anyone tell me why? I've started with haskell today so please go easy on the explanations. I've tried to run it like: runghc test.hs ghc test.hs but with: ghci < test.hs it gives this one: <interactive>:1:10: parse error on input `=' Thanks

    Read the article

  • Java: design problem with final-value and empty constructor

    - by HH
    $ javac InitInt.java InitInt.java:7: variable right might not have been initialized InitInt(){} ^ 1 error $ cat InitInt.java import java.util.*; import java.io.*; public class InitInt { private final int right; // Design Problem? // I feel the initialization problem is just due to bad style. InitInt(){} InitInt{ // Still the error, "may not be initialized" // How to initialise it? if(snippetBuilder.length()>(charwisePos+25)){ right=charwisePos+25; }else{ right=snippetBuilder.length()-1; } } public static void main(String[] args) { InitInt test = new InitInt(); System.out.println(test.getRight()); } public int getRight(){return right;} } Partial Solutions and Suggestions use "this" to access methods in the class, instead of creating empty constructor change final to non-final with final field value: initialize all final values in every constructor remove the empty constructor, keep your code simple and clean

    Read the article

  • ActionScript 3.0: placing code on stage/MC timelines a la AS2 instead of in classes

    - by BoltClock
    I'm aware that ActionScript 3.0 is designed from the ground up to be a largely object-oriented language and using it means less or even no timeline code in Flash documents. I'm quite experienced with OOP and am comfortable writing classes. However, since I mostly use Flash for animations, I hardly ever need to write ActionScript code other than for preloaders, subtitles, quality controls, website links and so on. In fact, I still set my Flash movies to use AS2 to this day because I'm used to gotoAndPlay()/gotoAndStop(), AS2 preloaders, subtitles, quality controls and even getURL(). Of course, I really want to move on now that practically everyone's on Flash Player 9 or 10 and now that I've dabbled with other OO languages like Java, C# and Objective-C too. I'm a complete newcomer to AS3 and am not very learned with AS2 either. Considering my current use of ActionScript, are there any cases where it's still OK to use very simple AS3 code in the timeline instead of moving code to a class, especially since moving to a class might mean unnecessarily increasing the number of LOC from 4 to 40? (Heck, is the latter case ('instead of ...') even a valid concern at all?)

    Read the article

  • Java: custom-exception-error

    - by HH
    $ javac TestExceptions.java TestExceptions.java:11: cannot find symbol symbol : class test location: class TestExceptions throw new TestExceptions.test("If you see me, exceptions work!"); ^ 1 error Code import java.util.*; import java.io.*; public class TestExceptions { static void test(String message) throws java.lang.Error{ System.out.println(message); } public static void main(String[] args){ try { // Why does it not access TestExceptions.test-method in the class? throw new TestExceptions.test("If you see me, exceptions work!"); }catch(java.lang.Error a){ System.out.println("Working Status: " + a.getMessage() ); } } }

    Read the article

  • How can ported code be detected?

    - by NiallJG
    If you port code over from one language to another, how can this be detected? Say you were porting code from c++ to Java, how could you tell? What would be the difference between a program designed and implemented in Java, and a near identical program ported over to Java?

    Read the article

  • Getting a char array from a vector<int>?

    - by Legend
    I am trying to pass a value from C++ to TCL. As I cannot pass pointers without the use of some complicated modules, I was thinking of converting a vector to a char array and then passing this as a null terminated string (which is relatively easy). I have a vector as follows: 12, 32, 42, 84 which I want to convert into something like: "12 32 42 48" The approach I am thinking of is to use an iterator to iterate through the vector and then convert each integer into its string representation and then add it into a char array (which is dynamically created initially by passing the size of the vector). Is this the right way or is there a function that already does this?

    Read the article

  • Add New Gist using the Github API

    - by Ben Shelock
    I'm making a small app in Adobe Air which I need to interact with the Github Gist API. However I'm kind of stuck. If you're not familiar with Adobe Air you can still help, the XMLHttpRequest javascript object can do cross domain requests, as there is no domain as such. So theres nothing Adobe Air specific here. Where I'm stuck is I think I need to authenticate myself then make the POST. I just don't understand it

    Read the article

  • Should I learn VB.NET or C#?

    - by Ravi
    Background I have decided to do my graduation project (yet to start) in .NET. Regarding it, I am bit confused about: what language should I learn: VB.NET or C#? What I have learnt from those who know it that both VB.NET and C# have: The same concepts VB.NET is simpler as it is more like English statements but also C# is simple too if you already know C (Which I do know) Question So considering some factors, e.g. career point of view, newness, challenging and beneficial, etc., what language should I choose? Please help me out. And clearly do justify your answer (whatever reason you have.) References (Extra) A little information about what project I am doing: It is a database file system. Technologies I'll be using are SQL Server, WPF, etc. I just love the concept of Database file system.So those who want to know more about Database file system, here are the links DBFS (This one is really good.Serves as primary reference for me) Towards A Single Folder Filesystem stackoverflow-What is a database file system? UPDATE1 : After some really good explained answers (actually all are good at their place), I have finally decided to go with C# for myself. Thank you all. Still, you are requested to put your opinion (Once it is reopened,of course) UPDATE2 : Question reopened and made community wiki.Thank you all.

    Read the article

  • Connect to Mongodb in python

    - by SpawnCxy
    I'm a little confused by the document when I tried to connect to the Mongodb.And I find it's different from mysql.I want to create a new database named "mydb" and insert some posts into it.The follows is what I'm trying. from pymongo.connection import Connection import datetime host = 'localhost' port = 27017 user = 'ucenter' passwd = '123' connection = Connection(host,port) db = connection['mydb'] post = {'author':'mike', 'text':'my first blog post!', 'tags':['mongodb','python','pymongo'], 'date':datetime.datetime.utcnow()} posts = db.posts posts.insert(post) #print str(db.collection_names()) And I got an error as pymongo.errors.OperationFailure: database error: unauthorized.How can I do the authorizing part?Thanks.

    Read the article

  • How do I create and use a junction table in Rails?

    - by Thierry Lam
    I have the following data: A post called Hello has categories greet Another post called Hola has categories greet, international My schema is: create_table "posts", :force => true do |t| t.string "name" t.datetime "created_at" t.datetime "updated_at" end create_table "categories", :force => true do |t| t.string "name" t.datetime "created_at" t.datetime "updated_at" end create_table "posts_categories", :force => true do |t| t.integer "post_id" t.integer "category_id" t.datetime "created_at" t.datetime "updated_at" end After reading the Rails guide, the most suitable relationship for the above seems to be: class Post < ActiveRecord::Base has_and_belongs_to_many :categories end class Category < ActiveRecord::Base has_and_belongs_to_many :posts end My junction table also seems to have a primary key. I think I need to get rid of it. What's the initial migration command to generate a junction table in Rails? What's the best course of action, should I drop posts_categories and re-create it or just drop the primary key column? Does the junction table have a corresponding model? I have used scaffold to generate the junction table code, should I get rid of the extra code? Assuming all the above has been fixed and is working properly, how do I query all posts and display them along with their named categories in the view. For example: Post #1 - hello, categories: greet Post #2 - hola, categories: greet, international

    Read the article

  • Java: how does isDirectory and isFile work in File-class?

    - by HH
    $ javac GetAllDirs.java GetAllDirs.java:16: cannot find symbol symbol : variable checkFile location: class GetAllDirs System.out.println(checkFile.getName()); ^ 1 error $ cat GetAllDirs.java import java.util.*; import java.io.*; public class GetAllDirs { public void getAllDirs(File file) { if(file.isDirectory()){ System.out.println(file.getName()); File checkFile = new File(file.getCanonicalPath()); }else if(file.isFile()){ System.out.println(file.getName()); File checkFile = new File(file.getParent()); }else{ // checkFile should get Initialized at least HERE! File checkFile = file; } System.out.println(file.getName()); // WHY ERROR HERE: checkfile not found System.out.println(checkFile.getName()); } public static void main(String[] args) { GetAllDirs dirs = new GetAllDirs(); File current = new File("."); dirs.getAllDirs(current); } }

    Read the article

  • PHP behaves weird, mixing up HTML markup.

    - by adardesign
    Thanks for looking on this problem. I have a page that is totally valid page, and there is a PHP loop that brings in a <li> for each entry of the table. When i check this page locally it looks 100% OK, but when veiwing the page online the left side bar (which creates this markup is broken randomly mixing <div>'s and <li>'s and i have no clue what the problem is. See page (problem is on the left side) php code <?php do { ?> <li class="clear-block" id="<?php echo $row_Recordset1['penSKU']; ?>"> <a title="Click to view the <?php echo $row_Recordset1['penName']; ?> collection" rel="<?php echo $row_Recordset1['penSKU']; ?>"> <img src="prodImages/small/<?php echo $row_Recordset1['penSKU']; ?>.png" alt="" /> <div class="prodInfoCntnr"> <div class="basicInfo"> <span class="prodName"><?php echo $row_Recordset1['penName']; ?></span> <span class="prodSku"><?php echo $row_Recordset1['penSKU']; ?></span> </div> <div class="secondaryInfo"> <span>As low as .<?php echo $row_Recordset1['price25000']; ?>¢ <!--<em>(R)</em>--></span> <div class="colorPlacholder" rel="<?php echo $row_Recordset1['penColors']; ?>"></div> </div> </div> <div class="additPenInfo"> <div class="imprintInfo"><span>Imprint area: </span><?php echo $row_Recordset1['imprintArea']; ?></div> <div class="colorInfo"><span>Available in: </span><?php echo $row_Recordset1['penColors']; ?></div> <table border="0" cellspacing="0" cellpadding="0"> <tr> <th>Amount</th> <th>500</th> <th>1,000</th> <th>2,500</th> <th>5,000</th> <th>10,000</th> <th>20,000</th> </tr> <tr> <td>Price <span>(R)</span></td> <td><?php echo $row_Recordset1['price500'];?>¢</td> <td><?php echo $row_Recordset1['price1000'];?>¢</td> <td><?php echo $row_Recordset1['price2500'];?>¢</td> <td><?php echo $row_Recordset1['price5000'];?>¢</td> <td>Please Contact</td> <td>Please Contact</td> </tr> </table> </div> </a> </li> <?php } while ($row_Recordset1 = mysql_fetch_assoc($Recordset1)); ?>

    Read the article

  • New to web development - backend questions

    - by James
    I'm new to web development although I'm confident in the roadmap for the front-end. I need direction on two things: Basic architecture Back-end technologies For architecture, what do I need to get started? From what I know, its: Get a domain name registered (godaddy?) Find a web host ??? anything else? or start developing the site? I don't think its that easy, there must be something I'm missing, right? For the back-end technologies, I have application development experience with Java and Python, but how likely is it to find a back-end hosting site that supports these languages over PHP? Is PHP a better choice? If I stick with what I know for the back-end, am I sabotaging myself later on? If I need help, how is the market for a python/java developer vs. a php developer? What do I need to know about databases? I have some basic SQL experience. Do hosting sites have limitations on the type of databases or bandwidth I need to worry about? I'm working through some of the common sites: StackOverflow, Sitepoint forums, Google, etc...are there other resources I should use?

    Read the article

  • Can someone explain me implicit parameters in Scala?

    - by Oscar Reyes
    And more specifically how does the BigInt works for convert int to BigInt? In the source code it reads: ... implicit def int2bigInt(i: Int): BigInt = apply(i) ... How is this code invoked? I can understand how this other sample: "Date literals" works. In. val christmas = 24 Dec 2010 Defined by: implicit def dateLiterals(date: Int) = new { import java.util.Date def Dec(year: Int) = new Date(year, 11, date) } When int get's passed the message Dec with an int as parameter, the system looks for another method that can handle the request, in this case Dec(year:Int) Q1. Am I right in my understanding of Date literals? Q2. How does it apply to BigInt? Thanks

    Read the article

  • php slideshow sample

    - by serhio
    I try to do a simple image slideshow in php (just cycle images, no links, no other effects). after some googling I found the following in net: <HTML> <HEAD> <TITLE>Php Slideshow</TITLE> <script language="javascript"> var speed = 4000; // time picture is displayed var delay = 3; // time it takes to blend to the next picture x = new Array; var y = 0; <?php $tel=0; $tst='.jpg'; $p= "./images"; $d = dir($p); $first = NULL; while (false !== ($entry = $d->read())) { if (stristr ($entry, $tst)) { $entry = $d->path."/".$entry; print ("x[$tel]='$entry';\n"); if ($first == NULL) { $first = $entry; } $tel++; } } $d->close(); ?> function show() { document.all.pic.filters.blendTrans.Apply(); document.all.pic.src = x[y++]; document.all.pic.filters.blendTrans.Play(delay); if (y > x.length - 1) y = 0; } function timeF() { setTimeout(show, speed); } </script> </HEAD> <BODY > <!-- add html code here --> <?php print ("<IMG src='$first' id='pic' onload='timeF()' style='filter:blendTrans()' >"); ?> <!-- add html code here --> </BODY> </HTML> but it displays only the first image from the cycle. Do I something wrong? the resulting HTML page is: <HTML> <HEAD> <TITLE>Php Slideshow</TITLE> <script language="javascript"> var speed = 4000; // time picture is displayed var delay = 3; // time it takes to blend to the next picture x = new Array; var y = 0; x[0]='./images/under_construction.jpg'; x[1]='./images/BuildingBanner.jpg'; x[2]='./images/littleLift.jpg'; x[3]='./images/msfp_smbus1_01.jpg'; x[4]='./images/escalator.jpg'; function show() { document.all.pic.filters.blendTrans.Apply(); document.all.pic.src = x[y++]; document.all.pic.filters.blendTrans.Play(delay); if (y > x.length - 1) y = 0; } function timeF() { setTimeout(show, speed); } </script> </HEAD> <BODY > <!-- add html code here --> <IMG src='./images/under_construction.jpg' id='pic' onload='timeF()' style='filter:blendTrans()' ><!-- add html code here --> </BODY> </HTML>

    Read the article

  • ArrayList in java

    - by fatih-yilmaz
    ArrayList<String> veri1 = new ArrayList<String>(); String[] veri2 = {"Fatih", "Ferhat", "Furkan"}; How can i add "veri2" to "veri1" like one element ? I mean if i call veri.get(0), it returns veri2.. Regards.

    Read the article

  • best way to switch between secure and unsecure connection without bugging the user

    - by Brian Lang
    The problem I am trying to tackle is simple. I have two pages - the first is a registration page, I take in a few fields from the user, once they submit it takes them to another page that processes the data, stores it to a database, and if successful, gives a confirmation message. Here is my issue - the data from the user is sensitive - as in, I'm using an https connection to ensure no eavesdropping. After that is sent to the database, I'd like on the confirmation page to do some nifty things like Google Maps navigation (this is for a time reservation application). The problem is by using the Google Maps api, I'd be linking to items through a unsecure source, which in turn prompts the user with a nasty warning message. I've browsed around, Google has an alternative to enterprise clients, but it costs $10,000 a year. What I am hoping is to find a workaround - use a secure connection to take in the data, and after it is processed, bring them to a page that isn't secure and allows me to utilize the Google Maps API. If any of you have a Netflix account you can see exactly what I would like to do when you sign-in, it is a secure page, which then takes you to your account / queue, on an unsecure page. Any suggestions? Thanks!

    Read the article

  • Advice needed from PHP/Cake PHP expert

    - by Hiro
    I'm very new to programming (besides SQL and databases), but I ultimately want to master Cake PHP for web development. Now, given how new I am, I'm rather lost as to how I get started. Down the road, I want to use MVC framework so that I help myself be disciplined in the way I build. However, I know basic knowledge of PHP and OOP PHP are required. So my question is this: what are the right steps to mastering Cake PHP? I don't want to skip critical phases of learning before learning to Cake PHP. At the same time, I don't want to spend more time than required learning PHP if I can learn it directly through Cake PHP knowledge. Any advice would be appreciated.

    Read the article

  • Storing simulation results in a persistent manner for Python?

    - by Az
    Background: I'm running multiple simuations on a set of data. For each session, I'm allocating projects to students. The difference between each session is that I'm randomising the order of the students such that all the students get a shot at being assigned a project they want. I was writing out some of the allocations in a spreadsheet (i.e. Excel) and it basically looked like this (tiny snapshot, actual table extends to a few thousand sessions, roughly 100 students). | | Session 1 | Session 2 | Session 3 | |----------|-----------|-----------|-----------| |Stu1 |Proj_AA |Proj_AB |Proj_AB | |----------|-----------|-----------|-----------| |Stu2 |Proj_AB |Proj_AA |Proj_AC | |----------|-----------|-----------|-----------| |Stu3 |Proj_AC |Proj_AC |Proj_AA | |----------|-----------|-----------|-----------| Now, the code that deals with the allocation currently stores a session in an object. The next time the allocation is run, the object is over-written. Thus what I'd really like to do is to store all the allocation results. This is important since I later need to derive from the data, information such as: which project Stu1 got assigned to the most or perhaps how popular Proj_AC was (how many times it was assigned / number of sessions). Question(s): What methods can I possibly use to basically store such session information persistently? Basically, each session output needs to add itself to the repository after ending and before beginning the next allocation cycle. One solution that was suggested by a friend was mapping these results to a relational database using SQLAlchemy. I kind of like the idea since this does give me an opportunity to delve into databases. Now the database structure I was recommended was: |----------|-----------|-----------| |Session |Student |Project | |----------|-----------|-----------| |1 |Stu1 |Proj_AA | |----------|-----------|-----------| |1 |Stu2 |Proj_AB | |----------|-----------|-----------| |1 |Stu3 |Proj_AC | |----------|-----------|-----------| |2 |Stu1 |Proj_AB | |----------|-----------|-----------| |2 |Stu2 |Proj_AA | |----------|-----------|-----------| |2 |Stu3 |Proj_AC | |----------|-----------|-----------| |3 |Stu1 |Proj_AB | |----------|-----------|-----------| |3 |Stu2 |Proj_AC | |----------|-----------|-----------| |3 |Stu3 |Proj_AA | |----------|-----------|-----------| Here, it was suggested that I make the Session and Student columns a composite key. That way I can access a specific record for a particular student for a particular session. Or I can merely get the entire allocation run for a particular session. Questions: Is the idea a good one? How does one implement and query a composite key using SQLAlchemy? What happens to the database if a particular student is not assigned a project (happens if all projects that he wants are taken)? In the code, if a student is not assigned a project, instead of a proj_id he simply gets None for that field/object. I apologise for asking multiple questions but since these are closely-related, I thought I'd ask them in the same space.

    Read the article

< Previous Page | 22 23 24 25 26 27 28 29 30 31 32 33  | Next Page >