How to count the number of lines in a file using C++?

Question

click here for the text file

I used the following code in Code::Blocks IDE. I get the number of lines as 2. Kindly help me with the code.

#include <iostream>
#include <fstream>
#include <string>

using namespace std;


int main()
{
ifstream in("readInt.txt", ios::in);
if(!in)
{
    cout << "Cannot open file";
    return 1;
}

string str;
int j=0;

while(in)
{
    getline(in,str);
    j++;
}

cout << "No of lines are: " << j;
in.close();
return 0;

}

Answer 1

You get a too small result because the line endings in your text file are encoded in a different way than the convention on your system.

Save or recreate the file with correct line endings for your system.

---

In the other direction, towards a too high result, the presented code

while(in)
{
    getline(in,str);
    j++;
}

… would produce a count of 1 for an empty file.

Instead do

while( getline(in,str) )
{
    j++;
}

Note: this remark only covers correctness, not efficiency.