Hello there, I've written a C++ function 'stod', which converts a C++ string to a double ..
You're free to use this code for EVERYTHING you want ..
There's only one thing which I'm not appreciating:
It's not allowed to sell this source code to anyone !

The usage is simple:

Getting

Dec 17, 2014 They do less work (and are less capable) than stream-based conversions, so if your compiler vendors know what they are doing, std::sto. will be faster than that and in fact will be no slower than C's strto./wcsto. (I really believe that it they ar. Jan 03, 2014  When I replace stoi with std::stoi, despite the fact that I included using namespace std; at the beginning of the program. All necessary libraries, iostream and string, are included. All necessary libraries, iostream and string, are included. Atoi,stoi is not part of the old c library in g so use the below options while compiling g -std=c11 -o myappcode myappcode.cpp Include the following file in your code #include. Parses str interpreting its content as a floating-point number, which is returned as a value of type float. If idx is not a null pointer, the function also sets the value of idx to the position of the first character in str after the number. The function uses strtod (or wcstod) to perform the conversion (see strtod for more details on the process). Note that the format accepted by these. I am using codeblocks and i can't make stoi function work. I read other questions regarding this issue but I couldn't solve it. Stoi CodeBlocks not working. Ask Question Asked 5 years, 8 months ago. This patch enables the following list of C11 functions and templates in the std namespace: stoi, stol, stoul, stoll, stof, stod.

If you pass a string which can't be turned into a number, the function's output is always '0' ..

Terra guitars. As you maybe already have found out (is this grammatically correct?) the function's name is inspired by the C-function 'atoi' ..

C++

Hope you find this code useful !!!

P.S.: Sorry if my English is bad, my native language is Dutch ..

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Just check out [my thread](http://www.daniweb.com/community-center/community-introductions/threads/205430/hello-from-tux) in the community introductions if you want to know more about me.

I know this can also be achieved using string streams (in a few lines of code), but my purpose was to do it without ..
I just tried to avoid as much standard C++ functions as I could ..
Off course this was only to test my programming skills and I know some of you are maybe saying that I'm reinventing the wheel, but it was only a test ..

William Hemsworth1,339

Or simply use the atof function :) but I see nothing wrong in reinventing the wheel too.

Lines 71 to 106 can be changed to:

Nice snippet.

Hey tux4life,

to reiterate William's comment, remember that chars (in single quotes) are just numbers, so you don't need big if's and switches to determine them.

To know if a char's a number, try something like:

So, as William said, if you do 'chr - '0' you'll get the actual numeric value of the char.

Reinventing the wheel is a fine way to think about what the standard functions do - as opposed to assuming they're magically and don't cost anything ;)

mvmalderen2,072

That's why I like this forum: You post your code, people give their opinion (+suggestions) about your code, you can make your code better/more efficient/shorter, and everyone has profit ..

Thank you for your replies !
I have learnt some useful things, I'll consider changing my code (bearing your suggestions in mind) ..

Getting Std And Sti To Work Dev C Free

BTW: Where do I have to post my changed code ?

As far as I know, you can't edit a snippet.
You will just have to post another snippet with the adjustments if you want to.

mvmalderen2,072

Yeah, surely I want to post the updated code, it's only a matter of time ..

Getting Std And Sti To Work Dev C Download

ExpertMod5K+
You should only really call a function like .c_str if you need to call a legacy C function. In this case atoi is a legacy C function but C++ has plenty of better options that you could use (actually the legacy C standard library has better options to use other than atoi). In a good C++ design you should be avoiding dropping down to C constructs like arrays if at all possible favouring vector<> or array<> instead.
This can be implemented entirely using the C++ library using a stringstream which has the advantage that you cen tell how much of the string has been converted.
  1. #include<iostream>
  2. #include<string>
  3. #include<sstream>
  4. using namespace std;
  5. int main()
  6. {
  7. string str = '131.90';
  8. string leftover;
  9. istringstream iss;
  10. int result;
  11. iss.str(str);
  12. iss >> result;
  13. iss >> leftover;
  14. cout << 'Converted: ' << result << ' Leftover: ' << leftover << endl;
  15. }
Output: Converted: 131 Leftover: .90
By simply changing the type of result to double I can convert the whole string.