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  • Some unclear PHP syntax

    - by serhio
    I am a PHP beginner and saw on the forum this PHP expression: $regex = <<<'END' / ( [\x00-\x7F] # single-byte sequences 0xxxxxxx | [\xC0-\xDF][\x80-\xBF] # double-byte sequences 110xxxxx 10xxxxxx | [\xE0-\xEF][\x80-\xBF]{2} # triple-byte sequences 1110xxxx 10xxxxxx * 2 | [\xF0-\xF7][\x80-\xBF]{3} # quadruple-byte sequence 11110xxx 10xxxxxx * 3 ) | ( [\x80-\xBF] ) # invalid byte in range 10000000 - 10111111 | ( [\xC0-\xFF] ) # invalid byte in range 11000000 - 11111111 /x END; Is this code correct? What do these strange (for me) constructions like <<<, 'END', /, /x, and END; mean? I recieve: Parse error: syntax error, unexpected T_SL in /home/vhosts/mysite.com/public_html/mypage.php on line X Thanks

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  • How to create a new File in Qt

    - by GG
    Hello friends, I am a Qt beginner and just got stuck with the problem. I am looking for a file SomePath/NewDirectoryA/NewFile.kml ( NewFile.kml will be the only file in NewDirectoryA, having this directory just to maintain semantics in the project ). If SomePath/NewDirectoryA/NewFile.kml exists then I will use it in my code and If it doesn't exist then I have to create it. If this File doesn't exist then this directory also doesn't exist in SomePath. So If only I have to create a file I can use QFile and open it in ReadWrite or WriteOnly mode. But the problem is I have to create the file with the directory itself. I tried with QFile with file name SomePath/NewDirectoryA/NewFile.kml but it didn't worked. Please suggest me a way in which I can create a new file( NewFile.kml ) in a new directory( NewDirectorA ) at a given location( SomePath ).

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  • How to provide Input to Dialogs designed by Qt Designer

    - by GG
    Hello, I am a Qt beginner and working with Qt Designer to develop some small UI elements. I read http://doc.trolltech.com/4.5/designer-using-a-ui-file.html to use these GUI elements in my code and using multiple inheritance approach. I am introducing bookmark feature which somewhat look like http://img293.imageshack.us/img293/3041/screenshotyb.png. Now the problem I am facing is How can I show all existing bookmark folders in the drop down(say folders are in a QVector). So my main problem is how can I pass some inputs to the UI element. I think I'm clear, please let me know if further explanation is required. Sorry for adding links directly, rich formatting in my browser is not working. Thanks in advance,

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  • Plural to Singular conversion trouble in Rails Migrations?

    - by Earlz
    Hi, I'm a beginner at Ruby On Rails and am trying to get a migration to work with the name Priorities So, here is the code I use in my migration: class Priorities < ActiveRecord::Migration def self.up create_table :priorities do |t| t.column :name, :string, :null => false, :limit => 32 end Priority.create :name => "Critical" Priority.create :name => "Major" Priority.create :name => "Minor" end def self.down drop_table :priorities end end This results in the following error though: NOTICE: CREATE TABLE will create implicit sequence "priorities_id_seq" for serial column "priorities.id" NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "priorities_pkey" for table "priorities" rake aborted! An error has occurred, this and all later migrations canceled: uninitialized constant Priorities::Priority Is this some problem with turning ies to y for converting something plural to singular?

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  • C++ - Where to code a member function for an inherited object.

    - by Francisco P.
    Hello! I have a few classes (heat, gas, contact, pressure) inheriting from a main one (sensor). I have a need to store them in a vector<Sensor *> (part of the specification). At some point in time, I need to call a function that indiscriminately stores those Sensor *. (also part of the specification, not open for discussion) Something like this: for(size_t i = 0; i < Sensors.size(); ++i) Sensors[i]->storeSensor(os) //os is an ofstream kind of object, passed onwards by reference Where and how shall storeSensor be defined? Is there any simple way to do this or will I need to disregard the specification? Mind you, I'm a beginner! Thanks for your time!

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  • output all data from db to a php page

    - by Sarit
    Hi, I'm a real beginner with PHP & mysql. Just for studying and for a simple example at school I would like to work this simple query and possibly output all the rows (or maybe even one) to a very basic output on a php page: <?php $user= "root"; $host="localhost"; $password=""; $database = "PetCatalog"; $cxn = mysqli_connect($host,$user,$password,$database) or die ("couldn’t connect to server"); $query = "SELECT * FROM Pet"; $result = mysql_query($cxn,$query) or die ("Couldn’t execute query."); $row = mysqli_fetch_assoc($result); echo "$result"; ?> this is the error message i've been getting: Warning: mysql_query() expects parameter 1 to be string, object given in C:\xampplite\htdocs\myblog\query.php on line 18 Couldn’t execute query. What should I do? Thanks!

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  • How do I convert a single char in string to an int

    - by Guest
    Keep in mind, if you choose to answer the question, I am a beginner in the field of programming and may need a bit more explanation than others as to how the solutions work. Thank you for your help. My problem is that I am trying to do computations with parts of a string (consisting only of numbers), but I do not know how to convert an individual char to an int. The string is named "message". for (int place = 0; place < message.size(); place++) { if (secondPlace == 0) { cout << (message[place]) * 100 << endl; } } Thank you.

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  • simple modification results in error

    - by lgwest
    When I tried to do a simple modification of the "hello android" program that eclipse adt plugin generates I get error and can't get the program to run again even if I restore the file to its original contents. The modification was that I changed a string in strings.xml. the line was: <string name="app_name">Todo List</string> and the app was runnable, then I changed it to <string name="app_name">Todo List1</string> and it was an error: [2010-04-21 23:18:03 - Todo_list] Error in an XML file: aborting build. And a new empty file also showed up called: strings.out.xml And then I can't get the prrogram back into runnable state even if I delete the empyt file and restore the original line, I'm a confused beginner of java, android and eclipse.

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  • C++ - How to call a member function for an inherited object.

    - by Francisco P.
    Hello! I have a few classes (heat, gas, contact, pressure) inheriting from a main one (sensor). I have a need to store them in a vector<Sensor *> (part of the specification). At some point in time, I need to call a function that indiscriminately stores those Sensor *. (also part of the specification, not open for discussion) Something like this: for(size_t i = 0; i < Sensors.size(); ++i) Sensors[i]->storeSensor(os) //os is an ofstream kind of object, passed onwards by reference Where and how shall storeSensor be defined? Is there any simple way to do this or will I need to disregard the specification? Mind you, I'm a beginner! Thanks for your time!

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  • Beginning Programmer Interested in Android - Should I Start with Java?

    - by Hudey
    I'm a beginner in programming. My experience so far is only in Actionscript 2 and 3. So I have a basic understanding of declaring variables, loops, arrays, if/then, do/while... I'm wanting to move to developing for Android phones so I'm wondering what suggestions people have for where to go next. Should I jump right to Android? Start with a 'beginning Java' approach? Or should I go some other route to beef up my knowledge of OOP concepts before launching into Android? I have my Dev environment set up and completed the Hello Android tutorial and I'm just wondering if I am going to be in over my head quickly?

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  • C++ for small, individual projects (i.e. hobby programming)

    - by Ygam
    I recently started C++. I am using PHP right now and decided to take a look at C++. Web programming had me working with a couple of languages, with a couple of people. I wanted to do programming where I only had to bother with one language and create small utility apps (mostly not web-based). I wanted a compiled, strongly-type language without memorizing a tome of classes. Basically I wanted to learn C++ for the following: mobile programming (I don't ever want to go touching Java, and I don't have a Mac for Objective C or IPhone SDK) small desktop apps like DTRs, POSs creating small desktop-based games creating small Air-like applications that can access the web for additional content I heard that C++ is not beginner-friendly and is mostly used for huge projects with lots of calculations and fine details (like 3D games). Is it practical or even possible for me to use C++ for the above cases? (Sorry, I haven't delved on C++ that much yet, so aside from "huge, monolithic project", I don't know any other uses for it)

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  • Python recursive function error: "maximum recursion depth exceeded"

    - by user283169
    I solved Problem 10 of Project Euler with the following code, which works through brute force: def isPrime(n): for x in range(2, int(n**0.5)+1): if n % x == 0: return False return True def primeList(n): primes = [] for i in range(2,n): if isPrime(i): primes.append(i) return primes def sumPrimes(primelist): prime_sum = sum(primelist) return prime_sum print (sumPrimes(primeList(2000000))) The three functions work as follows: isPrime checks whether a number is a prime; primeList returns a list containing a set of prime numbers for a certain range with limit 'n', and; sumPrimes sums up the values of all numbers in a list. (This last function isn't needed, but I liked the clarity of it, especially for a beginner like me.) I then wrote a new function, primeListRec, which does exactly the same thing as primeList, to help me better understand recursion: def primeListRec(i, n): primes = [] #print i if (i != n): primes.extend(primeListRec(i+1,n)) if (isPrime(i)): primes.append(i) return primes return primes The above recursive function worked, but only for very small values, like '500'. The function caused my program to crash when I put in '1000'. And when I put in a value like '2000', Python gave me this: RuntimeError: maximum recursion depth exceeded. What did I do wrong with my recursive function? Or is there some specific way to avoid a recursion limit?

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  • Nested WHILE loops in Python

    - by Guru
    I am a beginner with Python and trying few programs. I have something like the following WHILE loop construct in Python (not exact). IDLE 2.6.4 >>> a=0 >>> b=0 >>> while a < 4: a=a+1 while b < 4: b=b+1 print a, b 1 1 1 2 1 3 1 4 I am expecting the outer loop to loop through 1,2,3 and 4. And I know I can do this with FOR loop like this >>> for a in range(1,5): for b in range(1,5): print a,b 1 1 1 2 1 3 1 4 2 1 2 2 2 3 2 4 3 1 3 2 3 3 3 4 4 1 4 2 4 3 4 4 But, what is wrong with WHILE loop? I guess I am missing some thing obvious, but could not make out. P.S: Searched out SO, found few questions but none as close to this. Don't know whether this could classified as homework, the actual program was different, the problem is what puzzles me.

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  • Displaying shifts on a timetable/calendar using C#

    - by Dave Peters
    I am very much a beginner and have experience of SQL and a tiny amount of VBA. What I am looking to do is create a tool to pull shift times from a database and to display them on a timetable/calendar. It will be part of a desktop application that the (very tech illiterate) end users will use to view and amend shift patterns. In essence it will be a grid with days on one axis and people on the other (I would however like to have the blocks proportional to shift length). In my mind it would potentially be a simple Gantt chart. All computing stuff I’ve learnt has been through trial and error and I want to use this project to get a much better understanding of C# as well as to get to the end product. I have been reading around for ways to tackle the problem and my issue is creating the timetable framework to which I will bind the data. I am using Visual Studio 2010 and SQL Server 2008 R2. Do you know of good resources which will either start me on the road to designing my own interface or give a basic framework I can adapt? All the resources I’ve found so far have been in different languages or for web based applications. Thank you for your time.

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  • Which Perl modules can be installed just by copying lib files?

    - by elliot100
    I'm an absolute beginner at Perl, and am trying to use some non-core modules on my shared Linux web host. I have no command line access, only FTP. Host admins will consider installing modules on request, but the ones I want to use are updated frequently (DateTime::TimeZone for example), and I'd prefer to have control over exactly which version I'm using. By experimentation, I've found some modules can be installed by copying files from the module's lib directory to a directory on the host, and using use lib "local_path"; in my script, i.e. no compiling is required to install (DateTime and DateTime::TimeZone again). How can I tell whether this is the case for a particular module? I realise I'll have to resolve dependencies myself. Additionally: if I wanted to be able to install any module, including those which require compiling, what would I be looking for in terms of hosting? I'm guessing at the moment I share a VM with several others and the minimum provision I'd need would be a dedicated VM with shell access?

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  • Debugging Maya plug-ins: can't get output or debugger to engage

    - by brainjam
    I'm not a total beginner at Maya, but this is my first time trying to write a plug-in for it. I've downloaded the 30-day eval version of Maya2011 (32bit version on 64bit Windows 7), and have tried building a couple of plug-ins with VC 2008 Express. The first one is helloWorldCmd from the sample directory ..\devkit\plug-ins, and it basically doesn't work until you convert the line cout<<"Hello World"<<endl; to cerr<<"Hello World"<<endl;, but I can live with that. The second one is the SelectRingContext2 example from David Gould's book. The plug-in works as advertised, but I cannot get any debugging output from it. I've tried putting cout, cerr,printf, and MGlobal::displayInfo into the doIt() method, and can't get a peep. I also haven't figured out how to run the plug-in in a debugger. I'm afraid I'm missing something easy but slightly obscure, like a flag somewhere. Anybody out there have any hints? Edit: Turns out the action is happening in the redoIt() method. So I can get MGlobal::displayInfo and cerr producing output. Still don't know why cout and printf don't work, and I'm not sure how to run in the debugger. When I run maya -d (which some of the online advice says I should do) it just shows the output window but never loads the rest.

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  • Setting up DrJava to work through Friedman / Felleisen "A Little Java"

    - by JDelage
    All, I'm going through the Friedman & Felleisen book "A Little Java, A Few Patterns". I'm trying to type the examples in DrJava, but I'm getting some errors. I'm a beginner, so I might be making rookie mistakes. Here is what I have set-up: public class ALittleJava { //ABSTRACT CLASS POINT abstract class Point { abstract int distanceToO(); } class CartesianPt extends Point { int x; int y; int distanceToO(){ return((int)Math.sqrt(x*x+y*y)); } CartesianPt(int _x, int _y) { x=_x; y=_y; } } class ManhattanPt extends Point { int x; int y; int distanceToO(){ return(x+y); } ManhattanPt(int _x, int _y){ x=_x; y=_y; } } } And on the main's side: public class Main{ public static void main (String [] args){ Point y = new ManhattanPt(2,8); System.out.println(y.distanceToO()); } } The compiler cannot find the symbols Point and ManhattanPt in the program. If I precede each by ALittleJava., I get another error in the main, i.e., an enclosing instance that contains ALittleJava.ManhattanPt is required I've tried to find ressources on the 'net, but the book must have a pretty confidential following and I couldn't find much. Thank you all. JDelage

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  • A good matplot tutorial (from beginner to intermidiate)?

    - by morpheous
    Can anyone recommend a good matplot tutorial. I am a complete beginner - but have used similar software (matlab, R etc), in my halcyon days at University (i.e. a long time ago). A google search brings up a list of dubious quality, and the 'official' docs are too terse, or provide examples that are more 'edge case' (e.g. drawing dolphins swimming in a bubble), than one is likely to meet in practise. I want a manual that provides the following information in a well structured manner: Introduction to the data types Introduction to 2D plotting with some simple practical examples (simple 2D graphs) Introduction to 3D plotting with some simple practical examples (simple 2D graphs: contour and surface)

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  • Noob question about a statement in a Java program

    - by happysoul
    I am beginner to java and was trying out this code puzzle from the book head first java which I solved as follows and got the output correct :D class DrumKit { boolean topHat=true; boolean snare=true; void playSnare() { System.out.println("bang bang ba-bang"); } void playTopHat() { System.out.println("ding ding da-ding"); } } public class DrumKitTestDriver { public static void main(String[] args) { DrumKit d =new DrumKit(); if(d.snare==true) { d.playSnare(); } d.playTopHat(); } } Output is :: bang bang ba-bang ding ding da-ding Now the problem is that in that code puzzle one code snippet is left that I did not include..it's as follows d.snare=false; Even though I did not write it , I got the output like the book. I am wondering why is there need for us to set it's value as false even when we know the code is gonna run without it too !?? I am wondering what the coder had in mind ..I mean what could be the possible future use and motive behind doing this ? I am sorry if it's a dumb question. I just wanna know why or why not to include that particular statement ? It's not like there's a loop or something that we need to come out of. Why is that statement there ?

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  • Understanding how software testing works and what to test.

    - by RHaguiuda
    Intro: I've seen lots of topics here on SO about software testing and other terms I don't understand. Problem: As a beginner developer I, unfortunately, have no idea how software testing works, not even how to test a simple function. This is a shame, but thats the truth. I also hope this question can help others beginners developers too. Question: Can you help me to understand this subject a little bit more? Maybe some questions to start would help: When I develop a function, how should I test it? For example: when working with a sum function, should I test every input value possible or just some limits? How about testing functions with strings as parameters? In a big program, do I have to test every single piece of code of it? When you guys program do you test every code written? How automated test works and how can I try one? How tools for automated testing works and what they do? I`ve heard about unit testing. Can I have a brief explanation on this? What is a testing framework? If possible please post some code with examples to clarify the ideas. Any help on this topic is very welcome! Thanks.

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  • Basic problems (type inference or something else?) in Objective-C/Cocoa.

    - by Matt
    Hi, Apologies for how basic these questions are to some. Just started learning Cocoa, working through Hillegass' book, and am trying to write my first program (a GUI Cocoa app that counts the number of characters in a string). I tried this: NSString *string = [textField stringValue]; NSUInteger *stringLength = [string length]; NSString *countString = (@"There are %u characters",stringLength); [label setStringValue:countString]; But I'm getting errors like: Incompatible pointer conversion initializing 'NSUInteger' (aka 'unsigned long'), expected 'NSUInteger *'[-pedantic] for the first line, and this for the second line: Incompatible pointer types initializing 'NSUInteger *', expected 'NSString *' [-pedantic] I did try this first, but it didn't work either: [label setStringValue:[NSString stringWithFormat:@"There are %u characters",[[textField stringValue] length]]] On a similar note, I've only written in easy scripting languages before now, and I'm not sure when I should be allocing/initing objects and when I shouldn't. For example, when is it okay to do this: NSString *myString = @"foo"; or int *length = 5; instead of this: NSString *myString = [[NSString alloc] initWithString:"foo"]; And which ones should I be putting into the header files? I did check Apple's documentation, and CocoaDev, and the book I'm working for but without luck. Maybe I'm looking in the wrong places.. Thanks to anyone who takes the time to reply this: it's appreciated, and thanks for being patient with a beginner. We all start somewhere. EDIT Okay, I tried the following again: [label setStringValue:[NSString stringWithFormat:@"There are %u characters",[[textField stringValue] length]]] And it actually worked this time. Not sure why it didn't the first time, though I think I might have typed %d instead of %u by mistake. However I still don't understand why the code I posted at the top of my original post doesn't work, and I have no idea what the errors mean, and I'd very much like to know because it seems like I'm missing something important there.

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  • Using different numeric variable types

    - by DataPimp
    Im still pretty new so bear with me on this one, my question(s) are not meant to be argumentative or petty but during some reading something struck me as odd. Im under the assumption that when computers were slow and memory was expensive using the correct variable type was much more of a necessity than it is today. Now that memory is a bit easier to come by people seem to have relaxed a bit. For example, you see this sample code everywhere: for (int i = 0; i < length; i++) int? (-2,147,483,648 to 2,147,483,648) for length? Isnt byte (0-255) a better choice? So Im curious of your opinion and what you believe to be best practice, I hate to think this would be used only because the acronym "int" is more intuitive for a beginner...or has memory just become so cheap that we really dont need to concern ourselves with such petty things and therefore we should just use long so we can be sure any other numbers/types(within reason) used can be cast automagically? ...or am Im just being silly by concerning myself with such things?

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  • LINQ extention SelectMany in 3.5 vs 4.0?

    - by Moberg
    Hi When I saw Darins suggestion here .. IEnumerable<Process> processes = new[] { "process1", "process2" } .SelectMany(Process.GetProcessesByName); ( http://stackoverflow.com/questions/3059667/process-getprocessesbyname/3059733#3059733 ) .. I was a bit intrigued and I tried it in VS2008 with .NET 3.5 - and it did not compiling unless I changed it to .. IEnumerable<Process> res = new string[] { "notepad", "firefox", "outlook" } .SelectMany(s => Process.GetProcessesByName(s)); Having read some Darins answers before I suspected that it was me that were the problem, and when I later got my hands on a VS2010 with.NET 4.0 - as expected - the original suggestion worked beautifully. My question is : What have happend from 3.5 to 4.0 that makes this (new syntax) possible? Is it the extentionmethods that have been extended(hmm) or new rules for lambda syntax or? I've tried to search but my google-fu was not strong enough. Please forgive if the question is a bit naive and note that I've taged it as beginner :)

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  • a Facebook app beginner question

    - by Robert
    Dear all, I have written up my first php script to learn facebook API stuff.It goes like this: require_once('facebook/client/facebook.php'); $facebook = new Facebook('0fff13540b7ff2ae94be38463cb4fa67','8a029798dd463be6c94cb8d9ca851696'); http://stackoverflow.com/questions/ask $fb_user = $facebook-require_login(); ? Hello ' useyou='false' possessive='true' /! Welcome to my first application! I put "facebook.php" in the same directory as my php script. However,after I deploy the php on a web server and link it with facebook and run it,I got error saying: "Fatal error: Call to undefined method Facebook::require_login() in /home/a2660104/public_html/facebook-php-sdk-94fcb13/src/default.php on line 16" Could anyone help me a bit on this?I am a beginner to the facebook app programming.Thanks a lot!

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