Thread: void function that builds but error when trying to run

here is my error: LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/hw07.exe : fatal error LNK1120: 1 unresolved externals

The program will build but when I try to run it I get that error.

Problem:

Write a void function that reads in a specified number of float values and returns their average. A call to this function might look like
GetMeanof (5, mean)
where the first argument specifies the number of values to be read, and the second argument contains the results. Document the data flow of each parameter with /* in */, /* out */, or /* inout */.

here is what I have so far. what does this error mean?

thanks

Bryan

Code:

#include <iostream>

using namespace std;

void GetMeanOf(int count,
			   float mean)
int main()
{
	int totalNumber = count;
	float num1;
	float num2;
	float num3;
	float num4;
	float num5;
	float sum;

	{
		cout << "Enter 5 numbers: ";
		cin >> num1 >> num2 >> num3 >> num4 >> num5;
	}
	{
	sum = num1 + num2 + num3 + num4 + num5;
	count++;
}
mean = sum / totalNumber;

	cout << "Average is " << mean << endl;
}

Your program needs something to run it, namely, 'int main()'. The system expects this to be there as that is where it will enter the program.

And this will cause an infinite loop:

Code:

	while(count > 0)
	{
		cout << "Enter 5 numbers: ";
		cin >> num1 >> num2 >> num3 >> num4 >> num5;
	}

Note: The reason it compiles okay is that the compiler realizes that the function may be in a different source file somewhere, so it happily builds the object file. The linker is responsible for creating the executable though, and therefore will notice that there is no main in any of the object files.

I can create a program that gives me the average of 5 integers but I am having problem with this void stuff....could someone explain a little more cause the book has me lost.

Thanks

Originally posted by romeoz
I can create a program that gives me the average of 5 integers but I am having problem with this void stuff....could someone explain a little more cause the book has me lost.

Thanks

A 'void' function returns no value to the calling function. That's all. Nothing more. A void parameter means it takes no arguments when you call the function.

Quzah.

You're using the wrong variables for sum and average, they are the other way around. What you want is just a simple function, with a return type of void (nothing). Here's an example.

Code:

#include <iostream>
using namespace std;

void func(); // function prototype

int main()
{
          func(); // call func()
          return 0;
}

void func() // function definition
{
          cout << "func() called.\n";
          return; // optional, used to leave function and return to previous scope, ie main()
}