std::stof, std::stod, std::stold

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C++ Standard Library
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std::basic_string
Member functions basic_string::basic_string basic_string::operator= basic_string::assign basic_string::get_allocator Element access basic_string::at basic_string::operator[] basic_string::front (C++11) basic_string::back (C++11) basic_string::data basic_string::c_str Iterators basic_string::begin basic_string::cbegin (C++11) basic_string::end basic_string::cend (C++11) basic_string::rbegin basic_string::crbegin (C++11) basic_string::rend basic_string::crend (C++11) Capacity basic_string::empty basic_string::size basic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (C++11) Operations basic_string::clear basic_string::insert basic_string::erase basic_string::push_back basic_string::pop_back (C++11) basic_string::append basic_string::operator+= basic_string::compare basic_string::replace basic_string::substr basic_string::copy basic_string::resize basic_string::swap Search basic_string::find basic_string::rfind basic_string::find_first_of basic_string::find_first_not_of basic_string::find_last_of basic_string::find_last_not_of Constants basic_string::npos Non-member functions getline stoi stol stoll (C++11) (C++11) (C++11) stoul stoull (C++11) (C++11) stof stod stold (C++11) (C++11) (C++11) to_string (C++11) to_wstring (C++11)

Defined in header <string>
float       stof( const std::string& str, size_t *pos = 0 );	(1)	(C++11 feature)
double      stod( const std::string& str, size_t *pos = 0 );	(2)	(C++11 feature)
long double stold( const std::string& str, size_t *pos = 0 );	(3)	(C++11 feature)

Interprets a floating point value in a string str.

Function discards any whitespace characters until first non-whitespace character is found. Then it takes as many characters as possible to form a valid floating point representation and converts them to floating point value. The valid floating point value can be one of the following:

• decimal floating point expression. It consists of the following parts:

• (optional) plus or minus sign
• nonempty sequence of decimal digits optionally containing a decimal point character (defines significand)
• (optional) e or E followed with optional minus or plus sign and nonempty sequence of decimal digits (defines exponent)

• binary floating point expression. It consists of the following parts:

• (optional) plus or minus sign
• 0x or 0X
• nonempty sequence of hexadecimal digits optionally containing a decimal point character (defines significand)
• (optional) p or P followed with optional minus or plus sign and nonempty sequence of hexadecimal digits (defines exponent)

• infinity expression. It consists of the following parts:

• (optional) plus or minus sign
• INF or INFINITY ignoring case

• not-a-number expression. It consists of the following parts:

• (optional) plus or minus sign
• NAN or NAN(char_sequence) ignoring case of the NAN part. char_sequence can only contain alphanumeric characters. The result is a quiet NaN floating point value.

The index of the first unconverted character is stored in pos. If NULL is passed as pos, it is ignored.

Contents 1 Parameters 2 Return value 3 Exceptions 4 See also

[edit] Parameters

str	-	the string to convert
pos	-	address of integer to store the index of the first unconverted character

[edit] Return value

The string converted to the specified floating point type.

[edit] Exceptions

std::invalid_argument if no conversion could be performed

std::out_of_range if the converted value would fall out of the range of the result type.

[edit] See also

stoi stol stoll (C++11) (C++11) (C++11)	converts a string to an signed integer (function)
stoul stoull (C++11) (C++11)	converts a string to an unsigned integer (function)