Problem with re-using a stringstream object

Question

I\'m trying to use safe practices in handling input with numbers only in C++, so I use a stringstream object as so:

#include 
#include 

        

Answer 1

You need to reset the state of the stringstream. Generally, this involves two steps: clearing the buffer:

sstream.str("");

and resetting the error state flags:

sstream.clear();

If you don't clear the buffer, if you get an input like "123abc" then "abc" will still be in the stream when you try to read from it the next time.

You should also make sure to test the fail state of the stream (sstream.fail()) to ensure that the extraction was successful. If you want to be sure that the user only entered an integer (i.e., you want to prevent the user from inputting, say, "123abc", then you should test to make sure sstream.eof() is true.