• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
Squiffyk7

C++ skips a statement in it's first run

9 posts in this topic

Hello, i've been learning how to write in C++ using the tutorials on www.cplusplus.com for currently 3 days, so ofcourse my code will look very ammaturish. As I'm getting to grips with the syntax, i'm working on a simple program that lets you name how many films are your favourite, and specify what those films are called. Obviously its rather pointless, but as I said I'm practicing what i've learnt from the C++ syntax so far.

The error in my code is not preventing execution, it's just not doing what I want it to do.
 
// A program that lets you name "n" films.

#include <iostream>
#include <string>
#include <sstream>
using namespace std;

int main ()
{
    int n, i;
    string quant;

    cout << "How many favourite films do you have?" << endl;
    cin >> quant;
    stringstream(quant) >> n;
    cout << "What are your " << n << " favourite films?" << endl;
    string n_movie[n];

    for (i = 0; i < n; i ++)
    {
        getline(cin, n_movie[i]);
        cout << "Movie " << i << " is: " << n_movie[i] << endl;
    }


    return 0;
}
Once I run the code, I can enter my number but the console straight away also prints "Movie 0 is: " without allowing me to specify what movie movie 0 is. I can enter all movies up to movie n-1 as i should be able to.
Thanks in advance.
1

Share this post


Link to post
Share on other sites

Short answer: change [tt]cin >> quant;[/tt] to getline(cin, quant);. Using >> to extract from the stream leaves a carriage return hanging around in the stream that the first getline() tries to read as the first movie title.


And it works! Thanks, although I'm not to sure what's changed, I think I need to look further into what streams are before I move on.
0

Share this post


Link to post
Share on other sites

 

Short answer: change [tt]cin >> quant;[/tt] to getline(cin, quant);. Using >> to extract from the stream leaves a carriage return hanging around in the stream that the first getline() tries to read as the first movie title.


And it works! Thanks, although I'm not to sure what's changed, I think I need to look further into what streams are before I move on.

 

This documentation/tutorial can be a good read to refresh on the basic knowledge of what is happening: http://www.cplusplus.com/doc/tutorial/basic_io/

 

Basically what is happen is that cin>> extraction stops as soon as it finds a carriage return or even a blank space.  That is left inside the stream.  Then the next time you get input getline will see that still in the stream.  So it reads it in.

 

So the program is technically doing what it is "supposed" to do.  Just not what you expected it to do.  It does go through the for loop properly.  It just so happens that there is something left in the input stream the first time through.

Edited by Chad Smith
0

Share this post


Link to post
Share on other sites

In languages like C/C++, I/O is always one of the hairier things to mess with.  It's always worthwhile to check the nuances of the particular functions you're using in that area.

0

Share this post


Link to post
Share on other sites

This must be a common issue... I had the same problem with C#'s Console.Read() method... 

 

cin>>

reads <b>UP TO</b> the first enter/return, leaving the return itself in the input stream, to be read by your next input function.

 

getLine()

reads <b>and includes</b>the first enter/return, removing it from the input stream, so your next input function will have an empty input stream.

0

Share this post


Link to post
Share on other sites

string n_movie[n];
 
Or perhaps.....  
 
vector<string> n_movie;
n_movie.resize(n);
 
??


What's the question? Is there one? Yes I'd use a vector but it is likely the OP hasn't studied vectors yet so an array is fine with him learning.
1

Share this post


Link to post
Share on other sites

He's probably trying to indicate that initializing an array with local storage with a non-const array extent is not legal standard C++. It would be easier to tell if he employed the communication device commonly known as the complete sentence.

1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0