I just started using Microsoft Visual Studio 2010 for compiling my C++ code.
I have a project that is linked to another project called firmlib. To that end, I have linked the header files and libraries as described here:
http://www.steptools.com/support/stdev_docs/help/settings_vc10.html#header
In the new main that I wrote I call a method called readFromFile of the class Curve, as follows:
#include "stdafx.h"
#include <iostream>
#include "curve.h"
int _tmain(int argc, _TCHAR* argv[])
{
unsigned long n;
Curve discountCurve;
discountCurve.readCurve("fileName");
std::cout << "Give a natural number: " << endl;
std::cin >> n;
std::cout << "The faculty of " << n << " equals " << faculty(n) << ".\n";
return 0;
}
referring to the following method declaration (in Curve.h)
void readCurve(const char * filename){}
and implementation (in Curve.cpp) (I deleted some parts that are irrelevant for this post):
void Curve::readCurve(const char * filename){
cout << "Hi. This is the function Curve::readCurveat work.") << endl;
ifstream data;
marketData.open(filename);
marketData.close;
}
I built in the stream to the console in order to make sure that the source code is actually compiled. However, nothing is happening! So apparently the source code is not compiled.
Can anyone tell me what is going wrong here? I am puzzled ...
Thanks!
Related
I have a problem with the following code. I would like to write out data into different files in a loop. But when I instantiate ofstreams in a loop, my program silently crashes. I've boiled the code down, so that it doesn't do anything useful. It just demonstrates the behavior that I cannot explain:
#include <iostream>
#include <fstream>
using namespace std;
int main (int argc, char* argv[])
{
ofstream test_a("a.json");
cout << "test a" << endl;
ofstream test_b("b.json");
cout << "test b" << endl;
for (int idx = 0; idx < 3; idx++)
{
cout << "test " << idx << endl;
ofstream test("test_" + to_string(idx) + ".json");
}
return 0;
}
This is the output:
test a
test b
test 0
Nothing else, no error, nothing.
The first two ofstreams are apparently fine, but the loop stops somewhere after the cout. I am using Windows 10 and mingw:
gcc version 8.1.0 (x86_64-win32-seh-rev0, Built by MinGW-W64 project)
Thanks to the helpful comments I found that I linked a std library that must have been from an older version of my compiler. I fixed that and now it works.
I am new in VS code. I wrote a C++ code like one below. but unfortunately in the terminal or output panel I cannot get both of the string and variable value. in the terminal only variable's inputted value is showing. How to fix this?
#include <bits/stdc++.h>
int main()
{
int slices;
std::cin >> slices;
std::cout << "You got " << slices << " of pizzas" << std::endl;
return 0;
}
I'm trying to expand my C++ game hacking skills as when I was starting (2 years ago) I made a bad decision: continue in game hacking with vb.net instead of learning c++ (as I had some vb.net knowledge and 0 knowledge with other languages)
So, now as the very first steps I have to create my toolkit, where I will be using my own templates:
Nathalib.h (my template with all common functions for game hacking).
#pragma once
#include <iostream>
#include <Windows.h>
#include <string>
#include <TlHelp32.h>
#include <stdio.h>
using namespace std;
DWORD ProcessID;
int FindProcessByName(string name)
{
HWND hwnd = FindWindowA(0, name);
GetWindowThreadProcessId(hwnd, &ProcessID);
if (hwnd)
{
return ProcessID;
}
else
{
return 0;
}
}
Hack.cpp (obviously the cheat, will be different for every game).
#pragma once
#include "pch.h"
#include <iostream>
#include <Windows.h>
#include <string>
#include <Nathalib.h>
using namespace std;
int main()
{
While(True)
{
cout << FindProcessByName("Calculator") << endl;
getchar();
cout << "-----------------------------------" << endl << endl;
}
return 0;
}
Target.cpp (as we're not bad boys, I must provide my own target).
#include "pch.h"
#include <iostream>
#include <Windows.h>
#include <string>
using namespace std;
#define CHAR_ARRAY_SIZE 128
int main()
{
int varInt = 123456;
string varString = "DefaultString";
char arrChar[CHAR_ARRAY_SIZE] = "Long char array right there ->";
int * ptr2int;
ptr2int = &varInt;
int ** ptr2ptr;
ptr2ptr = &ptr2int;
int *** ptr2ptr2;
ptr2ptr2 = &ptr2ptr;
while(True) {
cout << "Process ID: " << GetCurrentProcessId() << endl;
cout << "varInt (0x" << &varInt << ") = " << varInt << endl;
cout << "varString (0x" << &varString << ") = " << varString << endl;
cout << "varChar (0x" << &arrChar << ") = " << arrChar << endl;
cout << "ptr2int (0x" << hex << &ptr2int << ") = " << ptr2int << endl;
cout << "ptr2ptr (0x" << hex << &ptr2ptr << ") = " << ptr2ptr << endl;
cout << "ptr2ptr2 (0x" << hex << &ptr2ptr2 << ") = " << ptr2ptr2 << endl;
cout << "Press ENTER to print again." << endl;
getchar();
cout << "-----------------------------------" << endl << endl;
}
return 0;
}
I don't know why the header file is not being recognized.
This is the correct way to include header files? Should I create a namespace/class/object for calling it?
It's the correct way creating a header file? Or I should create another kind of project/resource for this purpose?
How should I call my library methods? Like LibraryName.MethodName?
I just come from other languages and some ideas/features are not available in the other languages (that's why I'm interested in this one)
If there's something I forgot to add, please tell me and I will update
Thanks
There are multiple errors - please check your textbook.
You include your own headers with #include "". System headers are included with #include<>
The header file generally contains function declarations. Function bodies go into the corresponding .cpp file.
You call your library functions by their name. If they're in a namespace, that might mean the format is namespacename::functionname(arguments).
There are two ways to include headers, using "" or <>
with <> the file will be searched in the system search path (which is not the $PATH variabel, but the list of paths provided with `-I' together with standard headers already known by compiler) and included if found
with "" the file will be search in the current folder and in the system search path
Assuming your header is in th esame folder of hack.cpp, you should use
#include "Nathalib.h"
First off, your header lacks include guards, #pragma once only works with msvc++.
Your header file is probably not in PATH, so you need to specify it's path relative to your project. If your header file is in the same root as your cpp file, all you need to do is change the include statement for that header file to #include "Nathalib.h" otherwise you'll have to specify the relative path.
To add to other aswers- why you should put declaration of function in .h file, while its definition to .cpp file: Writing function definition in header files in C++
I suggest to find some c++ tutorials for example: http://www.tutorialspoint.com/cplusplus/cpp_functions.htm
You should learn tutorials first, making some exercises on simply code. Personally I prefer check then most simply code for new programming construct. Then more complicated.
After such learning you may use for reference also : http://www.cplusplus.com and https://en.cppreference.com/w/
I have tried to adapt my knowledge of modularity to Visual C++ however, upon what seems to be an endless search scouring for syntax, I simply can't get this right. Basically in this code, the menu is called first, once the user enters their choice (only coded option 1 thus far) to return that value to the main, which then steps into the if statement and calls fahrenheit. I am requesting the syntax for passing by reference, I know C#'s syntax for this, but not Visual C++
Here's the code.
// Test.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
void Celsius()
{
}
void fahrenheit()
{
cout << "Success!" << endl; //....Outputs this just to see if the module is being called properly.
}
int menu(int Mystring) //....I was testing this syntax to pass the variable.
{
cout << "What would you like to do : " << endl;
cout << "1) Fanreheit to Celsius" << endl;
cout << "2) Celsius to Fahrenheit" << endl;
cout << "Choice : " ;
cin >> Mystring;
return Mystring;
}
int main()
{
int celsius = 0;
int fahrenheit = 0;
int Mystring = 0;
menu(Mystring); //....Testing this syntax to pass Mystring to menu.
if (Mystring == 1) //....I was hoping the menu would return Mystring as value = 1.
{
fahrenheit(); //.......I want this to call fahrenheit module if Mystring = 1
}
}
The "things" you're talking about aren't called modules, but functions. That's a pretty big difference and I think you should know it, since you won't understand nearly any article without that knowledge.
That being cleared, the problem in your code is, that you pass the variable by value (int menu(int Mystring)), while - in order to change it inside the function - you need to pass it by reference or pointer:
int menu(int &Mystring)
There are plenty of articles about functions in C++. You should check them out probably.
I have a simple test program in C++ that prints out attributes of a circle
#include <iostream>
#include <stdlib.h>
#include "circle.h" // contains the Circle class
using namespace std;
void print_circle_attributes(float r) {
Circle* c = new Circle(r);
cout << "radius: " << c->get_radius() << endl;
cout << "diameter: " << c->get_diameter() << endl;
cout << "area: " << c->get_area() << endl;
cout << "circumference: " << c->get_circumference() << endl;
cout << endl;
delete c;
}
int main(int argc, const char* argv[]) {
float input = atof(argv[0]);
print_circle_attributes(input);
return 0;
}
when I run my program with the parameter 2.4 it outputs:
radius: 0.0
diameter: 0.0
area: 0.0
circumference: 0.0
I've previously tested the program without the parameter, but simply using static values, and it ran just fine; so I know there's nothing wrong with the class I made...
So what did I do wrong here?
argv[0] is the program name. You want argv[1] for the first argument.
Also, check that argc is at least two before trying to access it. You might also consider std::stoi, std::istringstream or strtod rather than atoi for conversion, since they can detect bogus input.
Finally, why are using new when an automatic variable will suffice? You should get out of that habit straight away, or spend the rest of eternity debugging memory leaks.
argv[0] is the name of the executable being invoked.
Your first command line parameter will be in argv[1].
To make sure that your program does not silently fail again, you should check how many parameters you actually have and if the atof returns a value, and show a message to the user explaining the issue accordingly.