How do I flush extraneous characters from cin?

Question

char buff[3];

cout<<"From: ";
cin.getline(buff, 3);

//something something

cout<<"To: ";
cin.getline(buff, 3);

How can I clear buffer at comment so extra chars don't go to my second cin?

Answer 1

One way is to use istream::ignore:

cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');

This will skip the maximum possible number of characters up until a newline is read.

For what it's worth, though, you should probably not be using istream::getline, as it works with raw C-style strings. A better option would be to use std::string and the free function std::getline:

std::string buffer;
getline(cin, buffer);

This will automatically read all the characters from stdin up until a newline.

Answer 2

Take a look at istream::ignore

Answer 3

#import<string.h>

memset(buf, 0, 3);

This will fill the buffer with zeros.