You need to either declare or define the function before you can use it. Otherwise, it doesn’t know that HelloWorld()
exists as a function.
Add this before your main function:
void HelloWorld();
Alternatively, you can move the definition of HelloWorld()
before your main()
:
#include <iostream>
using namespace std;
void HelloWorld()
{
cout << "Hello, World" << endl;
}
int main()
{
HelloWorld();
return 0;
}