Search Results

Search found 4685 results on 188 pages for 'cpp beginner'.

Page 40/188 | < Previous Page | 36 37 38 39 40 41 42 43 44 45 46 47  | Next Page >

  • What does the '&' operator do in C++?

    - by rascher
    n00b question. I am a C guy and I'm trying to understand some C++ code. I have the following function declaration: int foo(const string &myname) { cout << "called foo for: " << myname << endl; return 0; } How does the function signature differ from the equivalent C: int foo(const char *myname) Is there a difference between using string *myname vs string &myname? What is the difference between & in C++ and * in C to indicate pointers? Similarly: const string &GetMethodName() { ... } What is the & doing here? Is there some website that explains how & is used differently in C vs C++?

    Read the article

  • How does PHP work - literature

    - by Ondrej Slinták
    I'm interested in literature (articles on internet, in magazines, books, podcasts - I don't really mind anything) that describes how PHP works internally, about its gotchas and perhaps some advanced functions. Is there anything like this out there? I tried to search on Google, but majority of articles were about starting with PHP and its basic functions. Any input is really welcome as I'm trying to understand the language internally - I'm tired of my mindless typing of code without understanding its essence.

    Read the article

  • How do I implement multiple kinds of an object in OOP?

    - by Jeremy Rudd
    I have multiple kinds of an object, say Car for example. Do I have each kind in an inherited class/subclass of Car? Do I place these under a cartype namespace so as not to mess up the main namespace? Then later when I need an array of cars, should I declare it as var currentCars():Car or var currentCars():Object? Would the former support any subclass of Car?

    Read the article

  • Caesar Cipher in Java (Spanish Characters)

    - by Rodolfo
    I've reading this question, and I was wondering if Is there any way to consider the whole range of characters? For example, "á", "é", "ö", "ñ", and not consider " " (the [Space])? (For example, my String is "Hello World", and the standard result is "Khoor#Zruog"; I want to erase that "#", so the result would be "KhoorZruog") I'm sure my answer is in this piece of code: if (c >= 32 && c <= 127) { // Change base to make life easier, and use an // int explicitly to avoid worrying... cast later int x = c - 32; x = (x + shift) % 96; chars[i] = (char) (x + 32); } But I've tried some things, and it didn't work.

    Read the article

  • Is there a better (i.e vectorised) way to put part of a column name into a row of a data frame in R

    - by PaulHurleyuk
    I have a data frame in R that has come about from running some stats on the result fo a melt/cast operation. I want to add a row into this dataframe containing a Nominal value. That Nominal Value is present in the names for each column df<-as.data.frame(cbind(x=c(1,2,3,4,5),`Var A_100`=c(5,4,3,2,1),`Var B_5`=c(9,8,7,6,5))) > df x Var A_100 Var B_5 1 1 5 9 2 2 4 8 3 3 3 7 4 4 2 6 5 5 1 5 So, I want to create a new row, that contains '100' in the column Var A_100 and '5' in Var B_5. Currently this is what I'm doing but I'm sure there must be a better, vectorised way to do this. temp_nom<-NULL for (l in 1:length(names(df))){ temp_nom[l]<-strsplit(names(df),"_")[[l]][2] } temp_nom [1] NA "100" "5" df[6,]<-temp_nom > df x Var A_100 Var B_5 1 1 5 9 2 2 4 8 3 3 3 7 4 4 2 6 5 5 1 5 6 <NA> 100 5 rm(temp_nom) Typically I'd have 16-24 columns. Any ideas ?

    Read the article

  • Does C# support inner classes? [closed]

    - by Amy
    Possible Duplicates: Using Inner classes in C# Inner classes in C# Class declared inside of another class in C# Does C# support the concept of inner classes? If so, what are the benefits? Could someone please explain this to me?

    Read the article

  • Creating constant in Python

    - by zfranciscus
    Hi, Is there a way to declare a constant in Python. In java I will we can create constant in this manner: public static final String CONST_NAME = "Name"; What is the equivalent of the above java constant declaration in python ? Cheers,

    Read the article

  • Python: Beginning problems

    - by Blogger
    ok so basically i very new to programming and have no idea how to go about these problems help if you will ^^ Numerologists claim to be able to determine a person’s character traits based on the “numeric value” of a name. The value of a name is determined by summing up the values of the letters of the name, where ‘a’ is 1, ‘b’ is 2, ‘c’ is 3 etc., up to ‘z’ being 26. For example, the name “Zelle” would have the value 26 + 5 + 12 + 12 + 5 = 60 (which happens to be a very suspicious number, by the way). Write a program that calculates the numeric value of a single name provided as input. Word count. A common utility on Unix/Linux systems is a small program called “wc”. This program counts the number of lines, words (strings of characters separated by blanks, tabs, or new lines), and characters in a file. Write your own version of this program. The program should accept a file name as input and then print three numbers showing the count of lines, words, and characters in the file.

    Read the article

  • Command-line input causes SyntaxError

    - by coson
    Good Day, I have a simple Python question that I'm having brain freeze on. This code snippet works. But when I substitue "258 494-3929" with phoneNumber, I get the following error below: # Compare phone number phone_pattern = '^\d{3} ?\d{3}-\d{4}$' # phoneNumber = str(input("Please enter a phone number: ")) if re.search(phone_pattern, "258 494-3929"): print "Pattern matches" else: print "Pattern doesn't match!" ####################################################### Pattern does not match Please enter a phone number: 258 494-3929 Traceback (most recent call last): File "pattern_match.py", line 16, in <module> phoneNumber = str(input("Please enter a phone number: ")) File "<string>", line 1 258 494-3929 ^ SyntaxError: invalid syntax C:\Users\Developer\Documents\PythonDemo> By the way, I did import re and tried using rstrip in case of the \n What else could I be missing? Thanks in advance.

    Read the article

  • How do I get the current color of a fragment?

    - by Mason Wheeler
    I'm trying to wrap my head around shaders in GLSL, and I've found some useful resources and tutorials, but I keep running into a wall for something that ought to be fundamental and trivial: how does my fragment shader retrieve the color of the current fragment? You set the final color by saying gl_FragColor = whatever, but apparently that's an output-only value. How do you get the original color of the input so you can perform calculations on it? That's got to be in a variable somewhere, but if anyone out there knows its name, they don't seem to have recorded it in any tutorial or documentation that I've run across so far, and it's driving me up the wall.

    Read the article

  • SQLAlchemy automatically converts str to unicode on commit

    - by Victor Stanciu
    Hello, When inserting an object into a database with SQLAlchemy, all it's properties that correspond to String() columns are automatically transformed from <type 'str'> to <type 'unicode'>. Is there a way to prevent this behavior? Here is the code: from sqlalchemy import create_engine, Table, Column, Integer, String, MetaData from sqlalchemy.orm import mapper, sessionmaker engine = create_engine('sqlite:///:memory:', echo=False) metadata = MetaData() table = Table('projects', metadata, Column('id', Integer, primary_key=True), Column('name', String(50)) ) class Project(object): def __init__(self, name): self.name = name mapper(Project, table) metadata.create_all(engine) session = sessionmaker(bind=engine)() project = Project("Lorem ipsum") print(type(project.name)) session.add(project) session.commit() print(type(project.name)) And here is the output: <type 'str'> <type 'unicode'> I know I should probably just work with unicode, but this would involve digging through some third-party code and I don't have the Python skills for that yet :)

    Read the article

  • PDCurses TUI with C++ Win32 console application

    - by Bach
    I have downloaded pdcurses source and was able to successfully include curses.h in my project, linked the pre-compiled library and all good. After few hours of trying out the library, I saw the tuidemo.c in the demos folder, compiled it into an executable and brilliant! exactly what I needed for my project. Now the problem is that it's a C code, and I am working on a C++ project in VS c++ 2008. The files I need are tui.c and tui.h How can I include that C file in my C++ code? I saw few suggestions here but the compiler was not too happy with 100's of warnings and errors. How can I go on including/using that TUI pdcurses includes!? Thanks EDIT: I added extern "C" statement, so my test looks like this now, but I'm getting some other type of error #include <stdio.h> #include <stdlib.h> using namespace std; extern "C" { #include <tui.h> } void sub0(void) { //do nothing } void sub1(void) { //do nothing } int main (int argc, char * const argv[]) { menu MainMenu[] = { { "Asub", sub0, "Go inside first submenu" }, { "Bsub", sub1, "Go inside second submenu" }, { "", (FUNC)0, "" } /* always add this as the last item! */ }; startmenu(MainMenu, "TUI - 'textual user interface' demonstration program"); return 0; } Although it is compiling successfully, it is throwing an Error at runtime: 0xC0000005: Access violation reading location 0x021c52f9 at line startmenu(MainMenu, "TUI - 'textual user interface' demonstration program"); Not sure where to go from here. thanks again.

    Read the article

  • Dealing with multiple Javascript IF statements.

    - by Joey
    Is it possible to put multiple IF statements in Javascript? If so, I'm having a fair amount of trouble with the statement below. I was wondering if you can put another IF statement in between if (data == 'valid') AND else? I want to add another if data =='concept') between the two. if (data == 'valid') { $("#file").slideUp(function () { $("#file").before('<div class="approvedMessage">WIN WIN WIN!</div>'); setTimeout(ApprovedProof, 5000); }); function ApprovedProof() { $("#file").slideDown(); $('.approvedMessage').fadeOut(); } } else { $("#file").slideUp(function () { $("#file").before('<div class="deniedMessage">NO NO NO!</div>'); setTimeout(DeniedProof, 5000); }); function DeniedProof() { $("#file").slideDown(); $('.deniedMessage').fadeOut(); } }

    Read the article

  • Incorrect syntax near ','.

    - by jeffreyshek
    I get the following error from the SQL Script I am trying to run: Msg 102, Level 15, State 1, Line 10 Incorrect syntax near ','. This is the SQL script: IF NOT EXISTS (SELECT * FROM dbo.sysobjects WHERE id = OBJECT_ID(N'[dbo].HDDB_DataSource]') AND OBJECTPROPERTY(id, N'IsUserTable') = 1) BEGIN CREATE TABLE [dbo].[HDDB_DataSource]( [ID] [int] IDENTITY(1,1) NOT NULL, [Name] [nvarchar](255) NOT NULL, [Type] [nvarchar](50) NOT NULL, [XmlFileName] [nvarchar](255) NULL, [ConnectionString] [nvarchar](255) NULL), CONSTRAINT [PK_DataSource] PRIMARY KEY CLUSTERED ( [ID] ASC ) ON [PRIMARY] ) ON [PRIMARY] END I am using SQL Server 2005 if that helps. Jeff

    Read the article

  • Why is my GUI unresponsive while a SwingWorker thread runs?

    - by Starchy
    Hello, I have a SwingWorker thread with an IOBound task which is totally locking up the interface while it runs. Swapping out the normal workload for a counter loop has the same result. The SwingWorker looks basically like this: public class BackupWorker extends SwingWorker<String, String> { private static String uname = null; private static String pass = null; private static String filename = null; static String status = null; BackupWorker (String uname, String pass, String filename) { this.uname = uname; this.pass = pass; this.filename = filename; } @Override protected String doInBackground() throws Exception { BackupObject bak = newBackupObject(uname,pass,filename); return "Done!"; } } The code that kicks it off lives in a class that extends JFrame: public void actionPerformed(ActionEvent event) { String cmd = event.getActionCommand(); if (BACKUP.equals(cmd)) { SwingUtilities.invokeLater(new Runnable() { public void run() { final StatusFrame statusFrame = new StatusFrame(); statusFrame.setVisible(true); SwingUtilities.invokeLater(new Runnable() { public void run () { statusFrame.beginBackup(uname,pass,filename); } }); } }); } } Here's the interesting part of StatusFrame: public void beginBackup(final String uname, final String pass, final String filename) { worker = new BackupWorker(uname, pass, filename); worker.execute(); try { System.out.println(worker.get()); } catch (InterruptedException e) { e.printStackTrace(); } catch (ExecutionException e) { e.printStackTrace(); } } } So far as I can see, everything "long-running" is handled by the worker, and everything that touches the GUI on the EDT. Have I tangled things up somewhere, or am I expecting too much of SwingWorker?

    Read the article

  • Determing Python version at runtime

    - by Gekitsuu
    The problem I'm having is that I've written code that depends on features in python2.6 so I'm trying to build a check that will produce a useful error if someone tries to run it on a machine with python lower than 2.6. The code I put in to check for the specific version and match it should work fine but the problem I have is the interpreter on a 2.4 machine reads the file and sees a "finally" at the end of my try loop and errors out before it gets far enough into execution for my if statement to handle the version mismatch. Other than changing the magic line to specifically look for /usr/bin/python2.6 is there a way python can handle this sort of thing?

    Read the article

  • Connecting my flex application to Restlet webservices

    - 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?

    Read the article

  • Python: needs more than 1 value to unpack

    - by Rosarch
    What am I doing wrong to get this error? replacements = {} replacements["**"] = ("<strong>", "</strong>") replacements["__"] = ("<em>", "</em>") replacements["--"] = ("<blink>", "</blink>") replacements["=="] = ("<marquee>", "</marquee>") replacements["@@"] = ("<code>", "</code>") for delimiter, (open_tag, close_tag) in replacements: # error here message = self.replaceFormatting(delimiter, message, open_tag, close_tag); The error: Traceback (most recent call last): File "", line 1, in for shit, (a, b) in replacements: ValueError: need more than 1 value to unpack All the values tuples have two values. Right?

    Read the article

  • User Management: Managing users in user-defined "groups", database schema and logistics

    - by Kevin Brown
    I'm a noob, development wise and logistically-wise. I'm developing a site that lets people take a test... My client wants the ability for a user with the roll/privledge "admin" (a step below a super-admin) to be allowed to create users and only see/edit the users that they create... The users created in that "category" or group need some information that their superior provides. For example, I log in as a "manager", I have the ability to invite people to take the test, and manage those people. Before adding those people, I will have filled out a short survey about myself... Right now, the users that are invited will be asked some of the same questions as the manager. I'd like to cut down the redundancy by using the information put into the database by the manager and apply it to the invited users. How do I set up my database to work with this criterion? I'm a little confused about how to do this! Let me know if I can add more details... (This is a mysql and php app)

    Read the article

  • Iterating over key and value of defaultdict dictionaries

    - by gf
    The following works as expected: d = [(1,2), (3,4)] for k,v in d: print "%s - %s" % (str(k), str(v)) But this fails: d = collections.defaultdict(int) d[1] = 2 d[3] = 4 for k,v in d: print "%s - %s" % (str(k), str(v)) With: Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable Why? How can i fix it?

    Read the article

  • Show / Hiding Divs

    - by Rob
    After cobbling together a few questions I've managed to get this far to showing / hiding divs: $(document).ready(function(){ $('.box').hide(); $('#categories').onMouseOver(function() { $('.box').hide(); $('#div' + $(this).val()).show(); }); }); HTML: <div id="categories"> <div id="btn-top20"><a href="">Top 20 Villas</a></div> <div id="btn-villaspec"><a href="">Villa Specials</a></div> <div id="btn-staffpicks"><a href="">Our Staff Picks</a></div> </div> <div id="category-content"> <div id="divarea1" class="box"> Content 1 </div> <div id="divarea2" class="box"> Content 2 </div> <div id="divarea3" class="box"> Content 3 </div> </div> What am I missing?

    Read the article

  • jQuery: Div elements are not showing up

    - by Legend
    I am adapting the Coverflow technique to work with a div. Following is the html: <html> <head> <meta http-equiv="Content-type" content="text/html; charset=utf-8" /> <style type="text/css" media="screen"> body,html { margin: 0; padding: 0; background: #000; height: 100%; color: #eee; font-family: Arial; font-size: 10px; } div.magnifyme { height: 80px; padding: 80px; position: absolute; top: 0px; left: 0px; width: 8000px; } div.wrapper { margin: 0px; height: 470px; /*border: 2px solid #999;*/ overflow: hidden; padding-left: 40px; right: 1px; width: 824px; position: relative; } div.container {position: relative; width: 854px; height: 480px; background: #000; margin: auto;} div.nav {position: absolute; top: 10px; width: 20%; height: 10%; right: 1px; } div.magnifyme div { position: absolute; width: 300px; height: 280px; float: left; margin: 5px; position: relative; border: 2px solid #999; background: #500; } </style> <script type="text/javascript" src="jquery-1.3.2.js"></script> <script type="text/javascript" src="ui.coverflow.js"></script> <script type="text/javascript"> $(function() { $("div.magnifyme").coverflow(); $("#add").click(function() { location.reload(); $(".magnifyme").append("<div id=\"div5\">hello world</div>"); $("div.magnifyme").coverflow(); }); }); </script> </head> <body> <div class="container"> <div class="wrapper"> <div class="magnifyme"> <div id="div0">This is div 0</div> <div id="div1">This is div 1</div> <div id="div2">This is div 2</div> <div id="div3">This is div 3</div> <div id="div4">This is div 4</div> </div> </div> <div class="nav"> <button type="button" id="add">Add to Deck</button> </div> </div> </body> </html> The coverflow function (included as a js file in the head section) is here. When I click the button, I was expecting it to add a DIV to the already present deck. For some reason, it doesn't show the newly added DIV. I tried calling the coverflow() function after I added the new element but that didn't work either. Is there any way I can make this work?

    Read the article

< Previous Page | 36 37 38 39 40 41 42 43 44 45 46 47  | Next Page >