std::stod, std::stof, std::stold in C++

1. std::stod() : It convert string into double. Syntax:

   double stod( const std::string& str, std::size_t* pos = 0 );
   double stod( const std::wstring& str, std::size_t* pos = 0 );
   Return Value: return a value of type double
   Parameters
   str : the string to convert
   pos : address of an integer to store the 
   number of characters processed. This parameter can also be 
   a null pointer, in which case it is not used.
   

   Output:

   5.6
   

   Another Example : Output:

   5 5 5
   

   If conversion is not performed, an invalid_argument exception is thrown. If the value read is out of the range of representable values by a double an out_of_range exception is thrown. An invalid idx causes undefined behavior.
2. std::stof : It convert string into float. Syntax:

   float stof( const string& str, size_t* pos = 0 );
   float stof( const wstring& str, size_t* pos = 0 );
   Parameters
   str : the string to convert
   pos : address of an integer to store the number of characters processed
   This parameter can also be a null pointer, in which case it is not used.
   Return value: it returns value of type float.

   Example 1: Output:

   22.5
   

   Example 2: Output:

   5000.5
   

   If no conversion could be performed, an invalid_argument exception is thrown.
3. std::stold : It convert string into long double. Syntax:

   long double stold( const string& str, size_t *pos = 0 );
   long double stold (const wstring& str, size_t* pos = 0);
   Parameters : 
   str : the string to convert
   pos : address of integer to store the index of the first unconverted character.
   This parameter can also be a null pointer, in which case it is not used.
   Return value : it returns value of type long double.
   

   Examples 1: Output:

   500087
   

   Example 2:

2077.5