how would i go about converting a string to a double?
This is a discussion on converting a string to an int or double.. within the C++ Programming forums, part of the General Programming Boards category; how would i go about converting a string to a double?...
how would i go about converting a string to a double?
7. It is easier to write an incorrect program than understand a correct one.
40. There are two ways to write error-free programs; only the third one works.*
1. Use the atof function:
2. Use stringstreams:Code:#include <iostream> #include <string> #include <cstdlib> using namespace std; int main() { string str("19.874"); double d; // Use atof to convert string to double d = atof(str.c_str()); // Output double value cout << d << endl; return 0; }
Code:#include <iostream> #include <string> #include <sstream> using namespace std; int main() { string str("19.874"); stringstream sstr(str); double d; // Extract double value from stringstream sstr >> d; // Output double value cout << d << endl; return 0; }
I used to be an adventurer like you... then I took an arrow to the knee.
http://www.cppreference.com/stdstring/atof.html
this is how you can do it in C not C++ hope it helps
[edit1]
took me a little while to find the correct link.
if you saw this with the old link, sorry to confuse you.
here is the index to the site with good details
http://www.cppreference.com/index.html
if all else fails google it.
[/edit1]
Last edited by xviddivxoggmp3; 03-27-2005 at 01:14 PM.
"Hence to fight and conquer in all your battles is not supreme excellence;
supreme excellence consists in breaking the enemy's resistance without fighting."
Art of War Sun Tzu
thanks for that...
also how do you convert a double to a string?
using <sstream>:
Code:#include <sstream> using namespace std; string makeString(double d) { ostringstream ss; ss<<d<<flush; return ss.str(); }
Last edited by sean; 03-27-2005 at 05:30 PM. Reason: Improper Code Tag Use
here is another link i found that might be of assistance to you.
all i did again was run a search on google to find it.
it uses stringstream to convert from and to the formats your looking for.
http://pegasus.rutgers.edu/~elflord/...ingstream.html
"Hence to fight and conquer in all your battles is not supreme excellence;
supreme excellence consists in breaking the enemy's resistance without fighting."
Art of War Sun Tzu