Using getline properly

[Daleth]

The following code works for half the time when getting user input. However, sometimes if the user presses enter without entering anything, the program crashes. Sometimes, after typing a short command, and then a longer one the next time, the program again crashes. Other times the program crashes without pattern.

I have no idea what is causing this undefined behavior.

do{
		cout << endl << "What do I do next?" << endl;
		getline(cin,in2,'\n');
			//Convert all letters to lowercase for ease on the processor.
		for(int indx=0; indx<101; indx++){
			if(isupper(in2[indx]))	in2[indx]=tolower(in2[indx]);}
ProcCheckList(in2);
	}while(play);
          in2 = "";

[Yanson]

for(int indx=0; indx<101; indx++){

try this
for(int indx=0; indx< in2.length(); indx++){

[Daleth]

I implemented that, and I really thought that was the solution since I never noticed that...

But the problem still persists...

New code:

	do{
		cout << endl << "What do I do next?" << endl;
		getline(cin,in2,'\n');
			//Convert all letters to lowercase for ease on the processor.
		for(int indx=0; indx<in2.length(); indx++){
			if(isupper(in2[indx]))	in2[indx]=tolower(in2[indx]);}
		ProcCheckList(in2);
		in2 = "";
	}while(play);

[Chervil]

Maybe there is a problem elsewhere in the program?

[Daleth]

I'd like to think that, but I secluded this portion of code in main. I even commented out the call to "ProcCheckList."

#include <iostream>
#include <string>
#include <stdlib.h>
#include <conio.h>
#include <cctype>
//#include "redirect_V2.h"
	
using namespace std;


int main(int argc, char *argv[]){
	bool play=true;
	string in2;

//	Clean();
	cout << "Ugh... I feel so groggy. Where am I? I think I need some 'help' here..." << endl;

	do{
		cout << endl << "What do I do next?" << endl;
		getline(cin,in2,'\n');
			//Convert all letters to lowercase for ease on the processor.
		for(int indx=0; indx<in2.length(); indx++){
			if(isupper(in2[indx]))	in2[indx]=tolower(in2[indx]);}
//		ProcCheckList(in2);
	}while(play);
	
//	Clean();
	getch();
	return 0;
}

Oh, and please disregard my use of conio.h. This is an incomplete, old program I'm trying to fix up. I want to focus on this current problem first.

[LB]

Taken from http://stackoverflow.com/questions/313970/stl-string-to-lower-case

Make sure you #include <algorithm>

//Convert all letters to lowercase for ease on the processor.
for(int indx=0; indx<in2.length(); indx++){
	if(isupper(in2[indx]))	in2[indx]=tolower(in2[indx]);}
transform(in2.begin(), in2.end(), in2.begin(), ::tolower);
//ProcCheckList(in2); 

http://ideone.com/XZJHET

Try cout << in2 << endl; to see if it works for you.

[Daleth]

Wow, that worked like a charm. Thanks!

Though that does raise a question... What are the problems with "tolower" and "toupper?"

[LB]

I don't know of any problems other than not being able to use a custom locale. If you scroll down that stackoverflow page there is a similar example that uses locales.