C++ :: Why Does GetY Have To Be Declared After Struct Y Is Declared
Jan 30, 2013
struct x
{
y *GetY(); //error: what is "y"?
struct y
{
};
};
Why does GetY have to be declared after struct y is declared? I thought order of class members in C++ did not matter? Does it have to do with the way parsing is done?
EDIT: It also doesn't work if I typename x::y *GetY();, which makes even less sense to me.
EDIT: It works if I forward declare, but this goes against everything I know about C++ classes...
I had a quick question regarding a program I am trying to complete. I have the basics worked out, and everything seems to be done, but I am running into two issues.
1= The program keeps telling me "Run-Time Check Failure #3 - The variable 'order' is being used without being initialized." and 2= When I reach my output screen I receive "Unhandled exception at 0x7751c41f in CISC 192 Project 3.exe: Microsoft C++ exception: std:Out_of_range at memory location 0x002eefb8.."
While the first one isn't necessarily a deal breaker the second one definitely is.
Code: // Bookstore Project 3.cpp : Defines the entry point for the console application. // Declarations #include "stdafx.h" #include <iostream> #include <iomanip> #include <cstdlib> #include <string> #include <istream>
I'm setting the Arduino to send data from it's analog pins through to my PC, but to keep it easier to manage, I'm trying to turn the analog reading into a character string, so instead of sending just the value, it instead sends "Pin 1: 345" for example, where 1 is the number of the analog pin in use, and 345 is the reading from that pin.
In my code below, the problem is getting my string variable to be recognized. When I try to verify the code, the error message I get reads "'string' does not name a type" yet when I compare it to other string variable examples on the internet, I can see no difference between mine and the ones online.
I've tried having the declaration in the loop, outside of the loop, and now at the start with the other declarations.
Program is not finished as I can't get passed read_data
Error: "error C2065: 'fin' : undeclared identifier error C2228: left of '.open' must have class/struct/union type is ''unknown-type''
#include "stdafx.h" #include <iostream> // for streams #include <iomanip> // for setw() #include <fstream> // for files #include <cstdlib> // for exit using namespace std; void read_data(int A[], int size)
I'm working on this program, and when i run it for 'p', 'P', or for a incorrect service code a error message pops up saying that "totalCost is being used without being initialized". I don't want to change it to switches, case, and breaks now because I've come too far to change it all. I have that variable right here just below.
#include <iomanip> #include <iostream> using namespace std; int main() { int acctCode; double nightCost; double totalCost;
#include <iostream> #include "sushi.h" using namespace std; int main() { do { ......sushi go; ......string x; <----------------------------Declared x here ......cout << "wanna use a banana?" << endl;
[Code ....
Error reads: 'x' was not declared in this scope.
How do I fix this?
P.S The sushi class does not matter, that is all perfect. Also, the dots are to represent my tabbing to make it easier to understand.
For some reason my compiler says "rename not declared in this scope" .... Isn't it declared in iostream? Or is rename only for C not C++? And if it is only for C how do I rename a file in C++ then?
#include <iostream> #include <cstdlib> using namespace std; int main(int argc, char* argv[]){ char oldname[] = "RomeTW.exe";
Is there any way to find the variables declared or defined in a c program and print those variables?? E.g. this is the code
#include<stdio.h> int main() { int a, b, c; printf("Enter two numbers to add"); scanf("%d%d",&a,&B)/>; c = a + b; printf("Sum of entered numbers = %d",c); return 0; }
I want to print all the variables been used. I used (gdb) info locals but its not giving the proper ouput.
I'm working through this neural network tutorial, unfortunately I get stuck trying to compile on line 28, saying "error: 'neuronNum' not declared in this scope." I seem to always get stuck on these kinds of errors, yet I don't understand because I though that the variable was declared and initialized within the for loop.
#include <iostream> #include <vector> using namespace std;
I'm trying to make a dynamic 2d array of a Tile Object I created, the Dynamic 2d array was working when I tested it as an int array but not that I gave it a type of Tile it is giving me the above error. I'm reading values from a .txt .
tile Tile; Tile **grid; grid = new Tile*[a]; for (int i = 0; i < a; ++i) { grid[i] = new Tile[b]; }
#include <iostream> #include <vector> #include <cmath> #include "ANN.h" using namespace std; const int NUM_HIDDEN_NEURONS = 3;
[Code] ....
So I am getting 2 errors. Here is both of them.
ANN.cpp: In member function "void ANN::JustDoIt()": ANN.cpp:36: error: "class std::vector<HiddenNeuron, std::allocator<HiddenNeuron> >" has no member named "SetWeights" ANN.cpp: In member function "void ANN::SetData(double, double)": ANN.cpp:85: error: "SetNeuronData" was not declared in this scope
I'm creating a payroll program and here is my code
Code:
#include <stdio.h> #include <stdlib.h> #include <string.h> #define REPORTHEADING1 " Employee Pay Hours Gross Tax Net " #define REPORTHEADING2 " Name Rate Worked Pay Due Pay }
[code]....
The errors I get are: variable or field PrintSummaryReport declared void in function voidPrintSummaryReport... cannot convert FILE to const car for argument to int printf(const char*...) which is for the following lines
Error10error C2248: 'std::thread::thread' : cannot access private member declared in class 'std::thread'c:program files (x86)microsoft visual studio 11.0vcincludexmemory06061ConsoleApplicationa
I have a small questions in the behavior of Structure, I have declare a structure with 10 components. Some of the components in the structure has already their value but when I use
The structure components in a function DLL function those value I set previously has been deleted or empty. I don't know what is the problem...
I have a header file that declares some fields as private, I then have a class that I need to compare two of the objects' information for equality but neither of them are the calling objects. I cannot alter the header file. How would I go about comparing private data fields? I will enter a brief bit of code for clarity.
Code: // Header File // stuff.h
class stuff { private: int* arr[20]; int size; }; bool equal (const stuff& a, const stuff& b);
I currently have globally declared arrays, which are accessed by multiple functions. I want to turn the program so that the arrays are no longer globally declared, but are passed to functions by reference.
I have one problem with passing the arrays: I found that, through debugging, I HAVE TO resize the array when I pass it by reference. For instance, I was using int a[10] when it was globally declared, when it is passed by reference with size 10, it does not work, instead it should be higher than 10 (certain number). Why is this happening? I do not get it...
I need writing my header files for my program of hangman. I've written what I could, but when I try parts out on their own to see if they work, I get errors. I haven't written my driver yet since I wanted to get this header working first. The first function needs to take the name of the file and read in its contents into the globally declared array. The second function takes no arguments and returns a word from the word list chosen at random. I guess my question is, would what I have so far work, or am I completely off? Here's what I have so:
randword.h #ifndef _randword_h #define _randword_h //static char words[100][50]; /* *Function: InitDictionary *This function reads in the dictionary of words and puts them into an array. */ void InitDictionary(void);
