c++ arguments aren't accepted into functions - c++

Question

My c++ program is this:
#include <iostream>
#include <cstdlib>
#include <dos.h>
using namespace std;
void arr(int pts,string *splt_msg){
for(int x=-1;x<pts-1;x++){
string input;
cout<<"Enter part "<<x<<endl;
cin>>input;
(*splt_msg)[x]=input;
}
}
void print_arr(string *splt_msg,int del,int parts){
for(int x=-1;x<parts-1;x++){
cout<<(*splt_msg)[x];
delay(del);
}
}
int main(){
cout<<"Parts in message: ";
int parts;
cin>>parts;
cout<<"Delay between parts(ms): ";
int del;
cin>>del;
parts--;
string splt_msg[parts];
string (*Parr)[parts]=&splt_msg;
arr(parts,Parr);
print_arr(Parr,del,parts);
return 0;
}
Here is the error code(on windows and mingw):
c:\Users\User\Desktop\c++>g++ -o program test1.cpp
In file included from test1.cpp:3:0:
c:\mingw\include\dos.h:54:2: warning: #warning "<dos.h> is obsolete; consider using <direct.h> instead." [-Wcpp]
^~~~~~~
test1.cpp: In function 'void arr(int, std::__cxx11::string*)':
test1.cpp:18:14: error: 'delay' was not declared in this scope
delay(del);
^
test1.cpp: In function 'int main()':
test1.cpp:32:17: error: cannot convert 'std::__cxx11::string (*)[parts] {aka std::__cxx11::basic_string<char> (*)[parts]}' to 'std::__cxx11::string* {aka std::__cxx11::basic_string<char>*}' for argument '2' to 'void arr(int, std::__cxx11::string*)'
arr(parts,Parr);
^
test1.cpp:33:27: error: cannot convert 'std::__cxx11::string (*)[parts] {aka std::__cxx11::basic_string<char> (*)[parts]}' to 'std::__cxx11::string* {aka std::__cxx11::basic_string<char>*}' for argument '1' to 'void print_arr(std::__cxx11::string*, int, int)'
print_arr(Parr,del,parts);
^
Does someone know what i have done wrong and the solution?
Thanks for the help, I'm just trying to write a simple program to test some concepts out like passing pointers into functions but it doesn't seem to be working.

Answer 1

This code is more C style then C++. You are doing difficult error prone things. Try using vectors and such
string splt_msg[parts];
should not even evaluate, as parts is not a constant expression.
Try using things like std::vector. and passing by reference. E.g.:
#include <iostream>
#include <string>
#include <vector>
#include <Windows.h>
template<typename T>
T Read() noexcept {
T output{};
std::cin >> output;
return output;
}
void arr(std::vector<std::string>& splt_msg) {
for (auto& msg : splt_msg) {
std::cout << "Enter part \n";
std::cin >> msg;
}
}
void print_arr(std::vector<std::string> const& splt_msg, int delay) {
for (auto& msg : splt_msg) {
std::cout << msg;
Sleep(delay);
}
}
int main() {
std::cout << "Parts in message: ";
auto parts = Read<int>();
std::cout << "Delay between parts(ms): ";
auto delay = Read<int>();
std::vector<std::string> splt_msg(parts);
arr(splt_msg);
print_arr(splt_msg, delay);
}
edit: or even better: use an object
#include <iostream>
#include <string>
#include <vector>
#include <Windows.h>
template<typename T>
T Read() noexcept {
T output{};
std::cin >> output;
return output;
}
class SplitMessage {
private:
std::vector<std::string> splitMessage;
public:
SplitMessage(size_t length) noexcept : splitMessage(length) {}
void GetData() noexcept;
void PrintData(int delay) const noexcept;
};
void SplitMessage::GetData() noexcept {
for (auto& msg : splitMessage) {
std::cout << "Enter part \n";
std::cin >> msg;
}
}
void SplitMessage::PrintData(int delay) const noexcept {
for (auto& msg : splitMessage) {
std::cout << msg;
Sleep(delay);
}
}
int main() {
std::cout << "Parts in message: ";
auto parts = Read<int>();
std::cout << "Delay between parts(ms): ";
auto delay = Read<int>();
SplitMessage splt_msg(parts);
splt_msg.GetData();
splt_msg.PrintData(delay);
}

Answer 2

Both functions require a std::string* (a pointer to a string) as first parameter, but both times you pass std::string*[] (an array of pointers to a string) as first paramater. The solution depends on what you want to achieve, but I guess, you want to call the function for one element of the array with an indexer: print_arr(Parr[0],del,parts);
Some other notes:
for(int x=-1;x<parts-1;x++){cout<<(*splt_msg)[x];...} will access the -1st character of a string, which is UB, but probably just crashes. Should be for(int x=0;x<parts;x++)
string splt_msg[parts]; is no valid C++, since parts is not constant at compile time.