Double to Const Char*
How can I convert a double into a const char, and then convert it back into a double?
I'm wanting to开发者_开发知识库 convert the double to a string, to write it to a file via fputs, and then when I read the file, it will need to be converted back into a double.
I'm using Visual C++ 2010 Express Edition.
If you just want to write the double
values to file, you can simply write it, without converting them into const char*
. Converting them into const char*
is overkill.
Just use std::ofstream
as:
std::ofstream file("output.txt")'
double d = 1.989089;
file << d ; // d goes to the file!
file.close(); //done!
Since you added C++ to your tags, I suggest you use std::stringstream
:
#include <sstream>
stringstream ss;
ss << myDouble;
const char* str = ss.str().c_str();
ss >> myOtherDouble;
You can use these functions to convert to and from:
template <class T>
bool convertFromStr(string &str, T *var) {
istringstream ss(str);
return (ss >> *var);
}
template <class T>
string convertToStr(T *var) {
ostringstream ss;
ss << *var;
return ss.str();
}
Example:
double d = 1.234567;
string str = convertToStr<double>(&d);
cout << str << endl;
double d2;
convertFromStr<double>(str, &d2);
cout << d2 << endl;
Use this funcition :
const char* ConvertDoubleToString(double value){
std::stringstream ss ;
ss << value;
const char* str = ss.str().c_str();
return str;
}
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