How can I detect if a line is empty?
I have:
1
2
3
4
5
I'm reading this with istream r so:
int n;
r >> n
I want to know when I reach the space between 4 and 5. I tried reading as char and using .peek() to detect \n but this detects the \n that goes after number 1 . The translation of the above input is: 1\n2\n3\n4\n\n5\n if I'm correct...
Since I'm going to manipulate the ints I rather read them as ints than using getline and then converting to int...
It could look like this:
#include <iostream>
#include <sstream>
using namespace std;
int main()
{
istringstream is("1\n2\n3\n4\n\n5\n");
string s;
while (getline(is, s))
{
if (s.empty())
{
cout << "Empty line." << endl;
}
else
{
istringstream tmp(s);
int n;
tmp >> n;
cout << n << ' ';
}
}
cout << "Done." << endl;
return 0;
}
output:
1 2 3 4 Empty line.
5 Done.
Hope this helps.