Unresolved external symbol in c++ - c++

#include <iostream>
#include <cstdlib>
using std::cout;
using std::endl;
using std::rand;
int man(){
int t=rand();
cout<<t<<endl;
return 0;
}
here is code for generate random number in c++ and i have mistake
1>c:\users\david\documents\visual studio 2010\Projects\random_function\Debug\random_function.exe : fatal error LNK1120: 1 unresolved externals
please help

Change man() to main().

Me, I think I'd change "man" to "main" and see what happens...

Related

LNK2001 error on atoi and stoi function with proper includes added

I have this project that throws LNK2001 error on using atoi while proper includes added:
#... //other headers
#include <cstdlib>
#include <string>
#include <cstring>
#include <cstdio>
#include <sstream>
#include <iostream>
BOOL main(int argc, char* argv[]){
ShowNumber(atoi(argv[1]));
return TRUE;
}
Error is: LNK2001: Unresolved external symbol _atoi
I do know that LNK error happens while a header confusion occurs. But i don't think that headers are the problem here. Is there anything in the project configuration or header conflict that may cause this to break? Also i get 15 other LNK2001 on using std::stoi.
Visual studio 2017 with 2015 or 2017 toolset.

error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup and Error 2 error LNK1120: 1 unresolved externals

I am getting the two errors when I try to compile my code. I have defined win32 consile application. I have not even yet started coding. My configurations are the following - Linker - subsytem - Console; Linker - Advanced - Entry Point - Blank.
error LNK2019: unresolved external symbol _main referenced in function
___tmainCRTStartup
Error 2 error LNK1120: 1 unresolved externals
I don't know what happened. Before everything was working fine but from today it does not. Do you have any idea how I can resolve it that?
My code so far is
// ConsoleApplication1.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "tbb/blocked_range.h"
#include "tbb/tbb.h"
#include <stdio.h>
#include <math.h>
#include <iostream>
#include "tbb/parallel_for.h"
#include <sstream>
#include <tbb/task_scheduler_init.h>
using namespace std;
#define PI 3.14159265
using namespace tbb;
// Sequential Execution
class Sequential
{
double * m;
double *n;
public:
Sequential(double n[], double m[]): n(n), m(m){}
void Partition()
{
}
int main(int argc, char** argv)
{
//double a = 5;
//double b = 4;
//Sequential g = Sequential(a,b);
return 0;
}
};
Thanks
The main function must be in the global namespace. C++ is not C#/Java where all functions must be inside classes.

VS 2012 Error LNK2019

I'm here so I can find a solution for my problem. I know this is too simple, but somehow I can't figure out where's the error in my code!
Here you have it:
AulaData.h
#ifndef AULADATA_H_
#define AULADATA_H_
#include <string>
using std::string;
class AulaData
{
private:
int dia;
public:
AulaData(int dia);
};
#endif
AulaData.cpp
#include "AulaData.h"
AulaData::AulaData(int dia)
{
}
And finally, my Main.cpp:
#include <vector>
#include "AulaData.h"
using namespace std;
int main(int argc, char* argv[])
{
AulaData a(12);
getchar();
return 0;
}
The error I'm getting is the following(something that never happened to me):
1>ConsoleApplication1.obj : error LNK2019: unresolved external symbol
"public: __thiscall AulaData::AulaData(int)" (??0AulaData##QAE#XZ)
referenced in function _main
Although if I define the class constructor without arguments, it'll work.
I'd appreciate a lot if someone could help me! :) I'm trully getting frustrated because all seems ok.
Thanks in advance!
I think that you must provide a default constructor as well if you create one with arguments.

error LNK2019: unresolved external symbol newbie needs tip

I am just probing some more advanced coding in C++, so imagine my frustration when I can't solve this:
1>Main.obj : error LNK2019: unresolved external symbol "int __cdecl playerAtk(void)" (? playerAtk##YAHXZ) referenced in function _main
1>C:\Users\Hezekiah Detinc\documents\visual studio 2010\Projects\Custom_1\Debug\Custom_1.exe : fatal error LNK1120: 1 unresolved externals
I had tried searching for an answer here, but the solutions I have found were too specific to be of any use for me.
If anyone can answer; What generally causes this problem? What are some solutions to fixing it?
This is my Main.cpp;
//Custom 1
//Include files that may be used. will cut out unused files in release.
#include <iostream>
#include <vector>
#include <string>
#include <cstdlib>
#include <ctime>
#include <algorithm>
#include "EnemyBaseClass.h"
#include "PlayerBaseClass.h"
using namespace std;
int main()
{
Enemy emy;
Player plr;
emy.enemyAtk();
emy.enemyDef();
emy.enemyHp();
plr.playerAtk();
plr.playerDef();
plr.playerHp();
int playerAtk();
cout << playerAtk();
cout << "You're attacked by a Monster!\n";
system(" pause ");
return 0;
}
If I need to post my headers or the other _.cpp files, let me know.
You declare and use playerAtk as a function (with no implementation, thus the undefined reference)
Change
int playerAtk();
...
cout << playerAtk();
to
int playerAtk;
...
cout << playerAtk;
(You probably want to initialize the variable)
The error is simple: You are using a function which you have declared, but you have not written any definition (Implementation). Check your source (.cpp) files.

Problem with SetSuspendState

I write a small application to enter the computer to Standby Mode:
#include "stdafx.h"
#include <windows.h>
#include <PowrProf.h>
int _tmain(int argc, _TCHAR* argv[])
{
SetSuspendState(FALSE, FALSE, FALSE);
return 0;
}
I get this error:
1>Standby.obj : error LNK2001: unresolved external symbol _SetSuspendState#12
1>C:\Documents and Settings\Sobak\Desktop\Standby\Release\Standby.exe : fatal error LNK1120: 1 unresolved externalsexternals
How can I fix it?
P.S.
I use Visual Studio 2005
Thank you in advance.
You should link your programm with the PowrProf.lib library. You could do it by adding the following string:
#pragma comment(lib, "PowrProf.lib")