string methods hard time

Hello people,
can anyone explain me why output from this program

Code:

#include <iostream>
#include <string>

using namespace std;

int main()
{
	string str = "This is, you shouldn't see this, just a test!";
	string :: size_type start, end;
	string delim = ",";

	start = str.find(delim);
	if (start == string::npos)
	{
		return 0;
	}
	end = str.find(delim, start+delim.length());
	str.erase(start, end+delim.length());
	cout << str;
	return 0;
}

is: "This is test!"(without quotes)?
I expected that characters between ',' (including them) would be removed.

The reason is that the erase() member function of std::string usually uses iterators. In your case, you are using the version that is index-based. This version takes a starting index, followed by the number of characters to erase.

You could simply switch to the iterator version:

Code:

str.erase(str.begin() + start, str.begin() + end + delim.length());

Or to use this:

Code:

str.erase(start, end+delim.length()-start);

Thanks laserlight, I didn't pay attention when reading documentation.