C++ Function calling fails - c++

Question

I get the following error when declaring a function:
Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++/c++example.cpp:23:5: error: no matching function for call to 'printstats'
printstats(&x, y);
^~~~~~~~~~
/Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++/c++example.cpp:10:6: note: candidate function not viable: no known conversion from 'const std::string *' (aka 'const basic_string<char, char_traits<char>, allocator<char> > *') to 'const std::string' (aka 'const basic_string<char, char_traits<char>, allocator<char> >') for 1st argument; remove &
void printstats(const std::string& x, int statnum);
^
/Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++/c++example.cpp:12:6: note: candidate function not viable: no known conversion from 'const std::string *' (aka 'const basic_string<char, char_traits<char>, allocator<char> > *') to 'char *' for 1st argument
void printstats(char * x, int stat_num)
^
1 error generated.
[Finished in 0.9s with exit code 1]
[shell_cmd: g++ "/Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++/c++example.cpp" -o "/Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++/c++example" && "/Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++/c++example"]
[dir: /Users/masterprogrammer/PycharmProjects/WolvesBatsRocks/c++]
[path: /anaconda3/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/Library/Frameworks/Python.framework/Versions/3.6/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin]
The function takes two inputs and I am calling it from main.
I am expecting an output which has the following formatting Strength: 7.
Here is the code:
// C program to illustrate
// call by value
#include <stdio.h>
#include <iostream>
#include <ctime> // For time()
#include <cstdlib> // For srand() and rand()
#include <string>
#include <cstring>
void printstats(const std::string& x, int statnum);
void printstats(char * x, int stat_num)
{
printf("%s: %d", x, stat_num);
}
int main(void)
{
const std::string&x = "Strength";
int y = 7;
// Passing parameters
printstats(&x, y);
return 0;
}

Answer 1

Your function prototype void printstats(const std::string& x, int statnum) and function definition void printstats(char * x, int stat_num) expect different parameters.
One expects a const string & as the first parameter and the other expects a char * as the first parameter.
Change both to have the same parameters and make sure your function call passes the appropriate argument(s) to the function.

Answer 2

You can't define an address type, but instead you can pass addresses of other variables which I think neither is what you're aiming to do.
& in method signature means call by reference which basically means inside the function the reference is used to access the actual argument used in the call.
To make it work, define a string and pass it directly.
std::string x= "Strength";
int y = 7;
printstats(x, y);

Answer 3

You really need to read a good introductory C++ book. It seems that you took an example from a C book, and tried to use it in C++ without understanding of what's happening.
I removed the unnecessary includes:
#include <stdio.h>
#include <string>
//Use a reference to string object instead of char pointer
void printstats(const std::string& x, int stat_num)
{
//printf is a C function that expects a C char* straing,
//so we need to convert the C++ string into it
printf("%s: %d", x.c_str(), stat_num);
}
int main(void)
{
//no need for "&" here - it's totally incorrect.
//It is an operation of taking an address of a variable.
const std::string x = "Strength";
int y = 7;
//no need for & here too
printstats(x, y);
return 0;
}
Output:
Strength: 7