Program shoudn't count comments and blank lines

[ep7network]

OK, I'm making some progress. My program does compile and output the number of line per code, but it shouldn't count comments and blank lines. I tried using (s.substr(0,2) == "//") as suggested but it didn't work. I definitely appreciate any recommendations and suggestions. Thanks guys.
This is my improved code:

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

const int A = 3;

int main()
{
string s;
ifstream myfile ("example.cpp");
int count = 0;
//int A = 3;
getline(myfile, s);

if (myfile.is_open())
{
while ( getline (myfile, s) ){
count++;
if (s[0] == '/' || s[0] == ' ' || s[0] == '#'){
count--;
}

}

}
cout << "This is your LOC: " << count << endl;
return 0;
}

[2kaud]

A line starting with a space (or a tab) is not necessarily a blank line - it could be part of a line indentation. A comment line starting with // might also have some preceding spaces or tabs. .length() returns the number of chars in the string so if this 0 then the line is blank. To find the position of the first non-space/tab then .find_first_not_of() can be used. See http://www.cplusplus.com/reference/s..._first_not_of/ A possible way of doing this could be

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

const string fnam = "example.cpp";
const char delim[] = { ' ', 9, 0 };

int main()
{
ifstream myfile(fnam.c_str());

	if (!myfile.is_open()) {
		cout << "Could not open file\n";
		return 1;
	}

int count = 0;
string s;
size_t pos;

	while (getline(myfile, s))
		if (s.length() && (pos = s.find_first_not_of(delim)) != string::npos)
			count +=  !(s.substr(pos, 2) == "//" || s[pos] == '#');

	cout << "This is your LOC: " << count << endl;
	return 0;
}