Back to General and Gameplay Programming

string to int

Craazer · 2003-05-09T09:03:49

Hi! This is probably often asked queston but the search engine doesn''t work right now... So how can I convert string to int or double? Converting backwards isn''t a problem becose I use wsprintf() for that, or is it a good solution?

General and Gameplay Programming Programming

Started by Craazer May 08, 2003 06:58 AM

14 comments, last by Craazer 20 years, 11 months ago

Craazer

122

Author

May 08, 2003 03:26 PM

quote:Original post by davepermen
just.. do it yourself..

read the first char. is it a number, get the number out of it. read next char, if its a number, multiply current value by 10, add new number to it, etc..

    bool isDigit(char chr) { return chr >= ''0'' && chr <= ''9''; }char* chr = beginning_of_string;while(*chr) { if(isDigit(chr)) break; ++chr; }int number = 0;do {  number *= 10;  number += *chr - ''0'';  chr++;}while(*chr && isDigit(chr));

something like this. i''m very very very tierd..:D

"take a look around" - limp bizkit
www.google.com

Thanks, actualy I just ended trying to do shometing similar becose the dot was kinda difficult to handle becose my solution took lot of speed. Well will be trying again later becose im very very tired too

civguy

308

May 08, 2003 04:02 PM

quote:Original post by Craazer
Probably would''t and the bad thing when searhing whit google is that strings and ints are in many langueges like java (what was the first search result).

That''s why you add ''C'' or ''C++'' to the search string.

billybob

134

May 08, 2003 05:03 PM

the inverse of sprintf is sscanf

Illumini

205

May 08, 2003 07:18 PM

itoa()
atoi()

other handy things ltoa(), atol(), etc

funny thing tho.. ftoa is missing, there is a atof tho.

itoa/ltoa do take a few extra things... a buffer to put string in... then the number, then a radix, usualy 10 (10 base number system is what we humans like to count in anyway

SabreMan

504

May 09, 2003 04:14 AM

quote:Original post by Illumini
itoa()
atoi()

Those functions are not recommended. atoi() yields undefined behaviour when the input cannot be converted, and itoa() isn''t a C function.

Qw3r7yU10p!

819

May 09, 2003 09:03 AM

just looking at ''Thinking in C++'' and found this code example:

  //: C03:stringConv.h// Chuck Allison''s string converter#ifndef STRINGCONV_H#define STRINGCONV_H#include <string>#include <sstream>template<typename T>T fromString(const std::string& s) {    std::istringstream is(s);    T t;    is >> t;    return t;}template<typename T>    std::string toString(const T& t) {    std::ostringstream s;    s << t;    return s.str();}#endif // STRINGCONV_H ///:~

quote:
Here’s a test program, that includes the use of the Standard Library complex number type:

  //: C03:stringConvTest.cpp#include "stringConv.h"#include <iostream>#include <complex>using namespace std;int main() {    int i = 1234;    cout << "i == \"" << toString(i) << "\"\n";    float x = 567.89;    cout << "x == \"" << toString(x) << "\"\n";    complex<float> c(1.0, 2.0);    cout << "c == \"" << toString(c) << "\"\n";    cout << endl;    i = fromString<int>(string("1234"));    cout << "i == " << i << endl;    x = fromString<float>(string("567.89"));    cout << "x == " << x << endl;    c = fromString< complex<float> >(string("(1.0,2.0)"));    cout << "c == " << c << endl;} ///:~

quote:
The output is what you’d expect:
i == "1234"
x == "567.89"
c == "(1,2)"
i == 1234
x == 567.89
c == (1,2)

string to int

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

string to int

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines