Getting input the rightway?

[xlsmnt]

I've recently started working with C++ and wondered if there was a "right" way for getting input from the console window. From what I've seen whenever I attempted to implement it more than once, cin>>string seems to fail on items of the "string" type. The use of getch()/scanf() isn't really satisfactory because getch() requires lots of garbage add ons to recognize the end of the string, and backspacing, while scanf() seems to run into the same problem as cin>>string. I've tried dozens of different methods for handling input from the console window, and most of them seem to have seemingly random errors if implemented more than once in the program. If anyone could provide suggestions or examples for getting input for the "string" type I would appreciate it.

[Banfa]

Look up getline in you C++ reference book

[xlsmnt]

Look up getline in you C++ reference book

It doesn't work correctly after multiple implementations, if I use, getline(cin, string); more than three times or so it begins to spit out random errors, and if I use it in a function that is implemented several times it spits out gibberish.

[Laharl]

You probably need to flush the input buffer between calls to getline with cin.flush().

[Banfa]

I do not think flush is a member of basic_istream (type of cin) (at least not in standard C++) it is a member of basic_ostream.

This makes sense all mirrors the badness of calling fflush on an input stream in C (it's bad don't do it).

I think the cin.ignore may be the function to use.

[weaknessforcats]

And don't use scanf() in C++. That's for C.

[xlsmnt]

I do not think flush is a member of basic_istream (type of cin) (at least not in standard C++) it is a member of basic_ostream.

This makes sense all mirrors the badness of calling fflush on an input stream in C (it's bad don't do it).

I think the cin.ignore may be the function to use.

cin.ignore() causes the function to eat the first character of every string after the first string, and I have no idea why. The upside is it is now providing me with strings instead of random ascii symbols.

[xlsmnt]

cin.ignore() causes the function to eat the first character of every string after the first string, and I have no idea why. The upside is it is now providing me with strings instead of random ascii symbols.

I found my own answer, the problem wasn't in getline, but in the variable I was referencing, for some reason my compiler didn't catch that I had a declared pointer "mystring" and a declared string "mystring" in the same function. So I wrote the getstring() function separately as

string getstring()
{
string input;
getline(cin, input);
return input;
}
 

This seems to actually work fine without any use of cin.clear() or cin.ignore()

[Ganon11]

Be careful; using getline like that, the program will look for any and all text from the start of the stream to the newline character ('\n, it's made when you press <Enter> or <Return>). It grabs that text, removes it from the stream, and returns it, but it leaves the '\n' still in the stream. This might mess you up if you call cin.get() or getline again after the original getline call. I ran into this problem a lot when I was learning C++.

[xlsmnt]

Be careful; using getline like that, the program will look for any and all text from the start of the stream to the newline character ('\n, it's made when you press <Enter> or <Return>). It grabs that text, removes it from the stream, and returns it, but it leaves the '\n' still in the stream. This might mess you up if you call cin.get() or getline again after the original getline call. I ran into this problem a lot when I was learning C++.

Well for some reason I'm not running into it now, does the system I'm compiling/running on effect that somehow?

Also I was wondering whether this

void getstring(string& ptr)
{
getline(cin, ptr);
}
int main()
{
string * ptr;
string mystring;
ptr = &mystring;
getstring(*ptr);
}
 

was the same as this

 
string getstring()
{
input string;
getline(cin, string);
return string;
}
int main()
{
string mystring;
mystring = getstring();
}