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  • Initialize a Variable Again.

    - by SoulBeaver
    That may sound a little confusing. Basically, I have a function CCard newCard() { /* Used to store the string variables intermittantly */ std::stringstream ssPIN, ssBN; int picker1, picker2; int pin, bankNum; /* Choose 5 random variables, store them in stream */ for( int loop = 0; loop < 5; ++loop ) { picker1 = rand() % 8 + 1; picker2 = rand() % 8 + 1; ssPIN << picker1; ssBN << picker2; } /* Convert them */ ssPIN >> pin; ssBN >> bankNum; CCard card( pin, bankNum ); return card; } that creates a new CCard variable and returns it to the caller CCard card = newCard(); My teacher advised me that doing this is a violation of OOP principles and has to be put in the class. He told me to use this method as a constructor. Which I did: CCard::CCard() { m_Sperre = false; m_Guthaben = rand() % 1000; /* Work */ /* Convert them */ ssPIN >> m_Geheimzahl; ssBN >> m_Nummer; } All variables with m_ are member variables. However, the constructor works when I initialize the card normally CCard card(); at the start of the program. However, I also have a function, that is supposed to create a new card and return it to the user, this function is now broken. The original command: card = newCard(); isn't available anymore, and card = new CCard(); doesn't work. What other options do I have? I have a feeling using the constructor won't work, and that I probably should just create a class method newCard, but I want to see if it is somehow at all possible to do it the way the teacher wanted. This is creating a lot of headaches for me. I told the teacher that this is a stupid idea and not everything has to be classed in OOP. He has since told me that Java or C# don't allow code outside of classes, which sounds a little incredible. Not sure that you can do this in C++, especially when templated functions exist, or generic algorithms. Is it true that this would be bad code for OOP in C++ if I didn't force it into a class?

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  • Choosing a Java IDE for homework assignments

    - by Andrew
    Can anyone recommend a light Java IDE that doesn't require you to make new projects each time you want to compile and run a program? I just want to be able to open java files and compile and run them. I have already tried Eclipse and NetBeans but both require you to make a new project each time you want to compile and run a program. Making a new project is fine for large scale projects but for small school assignments this just makes the process more tedious. Thanks

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  • Avoiding string copying in Lua

    - by Matt Sheppard
    Say I have a C program which wants to call a very simple Lua function with two strings (let's say two comma separated lists, returning true if the lists intersect at all, false if not). The obvious way to do this is to push them onto the stack with lua_pushstring, which works fine, however, from the doc it looks like lua_pushstring but makes a copy of the string for Lua to work with. That means that to cross over to the Lua function is going to require two string copies which I could avoid by rewriting the Lua function in C. Is there any way to arrange things so that the existing C strings could be reused on the Lua side for the sake of performance (or would the strcpy cost pale into insignificance anyway)? From my investigation so far (my first couple of hours looking seriously at Lua), lite userdata seems like the sort of thing I want, but in the form of a string.

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  • Java newbie problem: package with private access

    - by HH
    Pack.java imports pack.TestPack; but it cannot access it. I cannot understand why it cannot access the class despite the import. Error Pack.java:7: TestPack() is not public in pack.TestPack; cannot be accessed from outside package System.out.println(new TestPack().getHello()); ^ 1 error Pack.java import pack.TestPack; import java.io.*; public class Pack { public static void main(String[] args){ System.out.println(new TestPack().getHello()); } } TestPack.java package pack; import java.util.*; import java.io.*; public class TestPack { private String hello="if you see me, you ar inside class TestPack"; public String getHello(){return hello;} TestPack(){} }

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  • How do I keep from running out of memory on graphics for an Android app?

    - by user279112
    I've been working on an Android app in Eclipse, and so far, my program hasn't really grown past midget size. However I've already run into an issue with an Out of Memory error. You see, I've been using graphics comprised solely of bitmaps and PNGs in this program, and recently, when I tried to add a little bit more functionality to the program (mainly including a few more bitmaps and causing an extra sprite to be created), it started crashing in the graphics thread's constructor - sprite's constructor. When I tracked the problem down, it turned out to be an Out of Memory error that is seemingly caused by adding too many picture files to the program and creating Drawables out of them. This would be a problem, as I really don't have that many picture resources worked into that program...maybe 20 or so. I haven't even started to include sound yet. These images aren't all that fancy. My questions are this: 1) Are programs for the Android phone really that limited on how much memory they can employ, or is it probably something other than the 20-30 resource pictures causing that error? 2) If the memory for Android apps is so awful it can't even handle 20-30 picture resources being loaded into Drawables that exist at the same time, then how in the world are you supposed to make decent graphics and sound for that thing? Thanks.

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  • finally and return

    - by abson
    In the below example, class ex8 { public void show() { try { int a=10/0; return;} catch(ArithmeticException e) { System.out.println(e); return ;} finally { System.out.println("Finally"); } } public static void main(String[] args) { new ex8().show(); } } the output is: java.lang.ArithmeticException: / by zero Finally How is it that Finally gets printed in spite of return statement in catch?

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  • Getting started with microcontroller programming

    - by Trix
    I'm a fairly good programmer, knowledgeable in C, C++, Python, Ruby and PHP. I'd like to get started with microcontroller programming. I do know nothing about this topic. Microcontrollers are minimal computers on little circuit boards, right? I'm pretty new to electronics too, do I need to be an expert in it to do stuff with microcontrollers? What can I do with them? Would e.g.: A Pacman or Tetris game on an LCD be possible and not too hard? Where should I start? Basically I want to program something really small I can then take with me. This is my only real goal. Are microcontrollers the right thing for this, or are there better solutions? I'd like to do this for fun and as a hobby, I don't want to become a professional in it.

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  • taking integer input in java

    - by ruchir patwa
    I am actually new to java programming and am finding it difficult to take integer input and storing it in variables...i would like it if someone could tell me how to do it or provide with an example like adding two numbers given by the user..

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  • Running iPython from the OSX terminal.

    - by Az
    So I'm going through the matplotlib documentation and prepared to use the iPython interactive Python shell with ipython -pylab. However I get this: Az's MBP:~ Az$ ipython -pylab -bash: ipython: command not found Did I fail to install iPython? I used easy_install as advised. Any ideas?

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  • Why do I get "mysql_query(): supplied argument is not a valid"

    - by Brian Ojeda
    Why do I get a "mysql_query(): supplied argument is not a valid" for the first... $r = mysql_query($q, $connection); In the following code... $bId = trim($_POST['bId']); $title = trim($_POST['title']); $story = trim($_POST['story']); $q = "SELECT * "; $q .= "FROM " . DB_NAME . ".`blog` "; $q .= "WHERE `blog`.`id` = {$bId}"; $r = mysql_query($q, $connection); //confirm_query($r); if (mysql_num_rows($r) == 1) { $q = "UPDATE " . DB_NAME . ".`blog` SET `title` = '{$title}', `story` = '{$story}' WHERE `id` = {$bId}"; $r = mysql_query($q, $connection); if (mysql_affected_rows() == 1) { //Successful $data['success'] = true; $date['errors'] = false; $date['message'] = "You are the Greatest!"; } else { //Fail $data['success'] = false; $data['error'] = true; $date['message'] = "You can't do it fool!"; } } I also get an "mysql_num_rows(): supplied argument is not a valid MySQL result resource" error too. Side notes: I am using 1&1 Hosting (worst hosting ever), custom .htaccess file with one line text to enable PHP 5.2 (only why with 1&1 Hosting).

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  • Looking to eventually build a smartphone app...

    - by Brian L
    Hi all- I'm a young, inexperienced programmer (I've had a year of Java, some MATLAB, and HTML/CSS in school) but I've decided that to get better, I'm making it my goal to produce a simple smartphone app of some kind this year- probably either webOS or Android since I'm on a PC and can't afford a Mac just to write an iPhone app. So my question is, where do I start? I've read the threads about How to Write for Android and such, but I'm not sure I have enough Java experience to just jump right in. And then there's webOS which is based on JavaScript, correct? I guess I'd just like some input from more experienced folks. I have some Barnes and Noble book credit I'm looking to get rid of too, so if there's a guide you think would be useful, feel free to request. tl;dr: Programming newbie ultimately wants to build a simple smartphone app. Where do I start?

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  • mysqli and field types

    - by Mikk
    Hi, I'd like to know if there is a simple way to fetch data from mysql tables with "correct" data types? What i mean, if field type is for example INT or SMALLINT is it possible to pass those types directly to PHP as integers? I did some searching and found mysqli_fetch_fields, but for SMALLIT type is 2, for INT 3 and so on. It could be done that way, but it looks rather clumsy workaround. Is there any better way? I'm using PHP and mysqli. Thank you.

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  • Java: print field in an image of other class?

    - by HH
    DirectoryReader.java public class DirectoryReader { public static void main(String[] args) { File myFile = new File(path); FileObject fileThing = new FileObject(myFile); //How to print the value of the hello-field from fileThing? } } FileObject.java public class FileObject { FileObject (File fileThing) { String hello = "Hello Cosmos!"; } }

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  • Deploying my flex application

    - by Vatsala
    Hi, I am doing some trial testing awith Amazon ec2 boxes, deploying flex apps running on top of restlet powered webservices. I have this problem - Everytime i deploy the app to the cloud, I'm having to hardcode the IP address of the server into the ActionScript/MXML files (http://72.93.48.39:8080/xxx/abc/) and for certain reasons, i am forced to choose a different IP everytime. and i think its really not the right way to deploy the application. I would like to know what other people do in such scenarios? On thinking about it, i thought i could make it pickup values from the HTMLVars of the HTML wrapper. but that again has to be edited everytime again and again. will it be possible to be able to supply these values : server's ip address, server's port number(in case its not 8080 on some machine) at build time? if so can anyone give me a barbones sample build.xml just as an example?

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  • Java: how to have try-catch as conditional in for-loop?

    - by HH
    I know how to solve the problem by comparing size to an upper bound but I want a conditional that look for an exception. If an exception occur in conditinal, I want to exit. import java.io.*; import java.util.*; public class listTest{ public static void main(String[] args){ Stack<Integer> numbs=new Stack<Integer>(); numbs.push(1); numbs.push(2); for(int count=0,j=0;try{((j=numbs.pop())<999)}catch(Exception e){break;}&& !numbs.isEmpty(); ){ System.out.println(j); } // I waited for 1 to be printed, not 2. } } Some Errors javac listTest.java listTest.java:10: illegal start of expression for(int count=0,j=0;try{((j=numbs.pop())<999)}catch(Exception e){break;}&& ^ listTest.java:10: illegal start of expression for(int count=0,j=0;try{((j=numbs.pop())<999)}catch(Exception e){break;}&& ^

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  • Java method get the inheriting type

    - by DrDro
    I have several classes that extend C and I would need a method that accepts any argument of type C. But in this method I would like to know if I'm dealing with A or B. * public A extends C public B extends C public void goForIt(C c)() If I cast how can I retrieve the type in a clean way (I just read using getClass or instanceof is often not the best way). PS: Fell free to edit an explicit title. *Sorry but I can't type closing braces

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  • What benefits can Java developer have from moving to a *NIX platform?

    - by dave-keiture
    Hi everyone, A friend of mine is a Java developer, who's using *NIX for ages. He claims that *NIX is for real Java geeks, whereas WIN is for dummies (and I'm one of them, according to him) and girls. When I ask him to argue his position, and explain, what's so good for Java developer on *NIX, he starts talking about console, wget, curl and grep. But sorry, wget and curl analogues exist for the WIN platform as well. As for the console - I'm using FAR Commander, and have access to the command line when I need. Moreover, even if I decide moving to *NIX, I will certainly use Netbeans or Eclipse on it, so there will be no big difference. Guys, who use Java on *NIX, could you please give me some real killer examples, when *NIX (any util or technique) dramatically increases Java development productivity (in the way the hints are given in "The Pragmatic Programmer"), or, which is also important, gives more fun from the process. Thanks in advance!

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  • K&R Exercise 1-21 - Mental incomprehension.

    - by asdfg
    The "impossible" K&R exercise. "Write a program entab that replaces strings of blanks by the minimum number of tabs and blanks to achieve the same spacing. Use the same tab stops, say every n columns. Should n be a variable or a symbolic parameter?" The problem I'm having is, I'm unsure about how to even do this correctly. I know it's not very explanatory, but that's pretty much the problem here. Most of the examples I've seen have counted a number of blanks, and replaced those series with a tab, but this isn't what its asking, I reckon I understand what its asking, but currently feel unable to do this. Could anyone help :)

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  • How do you calculate accumulative time in C#?

    - by lima
    I want to calculate the time span between 2 times which I saved in a database. So literally I want to know the length of time between the 2 values. 14:10:20 - 10:05:15 = 02:05:05 So the result would be 02:05:05. How would I be able to achieve this using C#? 14:10:20 is the format I saved it in in my database.

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  • How to learn a language that has very little coverage?

    - by bennybdbc
    I recently came across the Kogut language, and was interested by it. However, the only website to gain information from is the sourceforge page that hosts the project. I had no idea how to even attempt to look at the language in more depth. So what I'm asking is, has anyone here learnt a language that doesn't have the thousands of resources that Ruby, Python etc. have? What would be the best method to do so?

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