Re: string to char array
* Felix85:
I am trying to make a command interpreter for a mud that i am working
on the problem i am having right now is that i cannot convert the
string into a char array.
Use std::string exclusively.
This is the error I am getting now:
In file included from src/mud.cpp:3:
src/command.h: In static member function `static void
command::getCommand(std::string)':
src/command.h:38: error: incompatible types in assignment of `const
char*' to `char[256]'
the third line is just an include statement for command.h
this is the code for command.h
#ifndef COMMAND_H
#define COMMAND_H
#include <iostream>
As a rule, don't include "nice to have" headers in headers.
#include <string>
#include <vector>
#include <cstring>
using namespace std;
See the FAQ item "Should I use using namespace std in my code?",
currently at <url:
http://www.parashift.com/c++-faq-lite/coding-standards.html#faq-27.5>.
In addition to what's mentioned in that item, the most important:
DON'T EVER PUT THAT IN A HEADER.
class command {
public:
static void tokenizer(string str, vector<string>& words, string
delimiter);
static void getCommand(string c);
private:
static vector<string> cmd;
};
Seems OK except for visual layout: it's not visually clear what's public
and what's private. The names could have been better, e.g.
tokenizer -> tokenize
getCommand -> command
cmd -> theCmd (or, for non-static, myCmd or cmd_).
vector<string> command::cmd;
No, you should not have this definition in a header file, because it
will be multiply defined (linker error) if the header is included in
more than one compilation unit. It belongs in an implementation file,
separately compiled. The easiest alternative, if you want to avoid a
separate implementation file, is to define inside a function, like
inline std::vector<std::string>& command::theCmdRef()
{
static std::vector<std::string> theCmd;
return theCmd;
}
void command::tokenizer(string str, vector<string>& words, string
delimiter)
Needs to be declared 'inline' if you want to have it in the header file,
so as to avoid multiple definition error.
Also declare the string arguments as 'std::string const& someName'.
{
string::size_type pos1 = 0;
string::size_type pos2 = str.find_first_of(delimiter);
words.push_back(str.substr(pos1 ,pos2 - pos1));
pos1 = pos2 + 1;
while(pos2 <= str.length()){
pos2 = str.find_first_of(delimiter, pos1);
if(pos2 > str.length()){
pos2 = str.length();
}
words.push_back(str.substr(pos1 ,pos2 - pos1));
pos1 = pos2 + 1;
pos2 += 1;
}
}
void command::getCommand(string c){
'inline', pass by ref.
tokenizer(c, cmd, " ");
if(cmd.size() == 1){
char oneWord[256];
Use a std::string (or reference to one).
oneWord = cmd[0].c_str();
Can't assign to array.
for(int i = 0; oneWord.length; i++){
oneWord[i].toLower();
}
cmd[0] = oneWord;
// Move North
if(cmd[0] = "n" || cmd[0] = "north"){
}
// Move South
if(cmd[0] = "s" || cmd[0] = "south"){
}
// Move East
if(cmd[0] = "e" || cmd[0] = "east"){
}
// Move West
if(cmd[0] = "w" || cmd[0] = "west"){
}
// Move Up
if(cmd[0] = "u" || cmd[0] = "up"){
}
// Move Down
if(cmd[0] = "d" || cmd[0] = "down"){
}
} else if(cmd.size() == 2){
} else {
cout << "invalid command!\n";
}
}
#endif
I suggest rethinking whether this really is a class: to me it looks like
a set of functions communicating via a global (the static 'cmd').
--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?