std::stoi, std::stol, std::stoll
| Defined in header  <string> | ||
| int       stoi( const std::string& str, std::size_t* pos = 0, int base = 10 ); int stoi( const std::wstring& str, std::size_t* pos = 0, int base = 10 ); | (1) | (since C++11) | 
| long      stol( const std::string& str, std::size_t* pos = 0, int base = 10 ); long stol( const std::wstring& str, std::size_t* pos = 0, int base = 10 ); | (2) | (since C++11) | 
| long long stoll( const std::string& str, std::size_t* pos = 0, int base = 10 ); long long stoll( const std::wstring& str, std::size_t* pos = 0, int base = 10 ); | (3) | (since C++11) | 
Interprets a signed integer value in the string str.
Function discards any whitespace characters (as identified by calling isspace()) until first non-whitespace character is found. Then it takes as many characters as possible to form a valid base-n (where n=base)  integer number representation and converts them to an  integer value. The valid   integer value consists of the following parts:
- (optional) plus or minus sign
-  (optional) prefix (0) indicating octal base (applies only when the base is 8 or 0)
-  (optional) prefix (0xor0X) indicating hexadecimal base (applies only when the base is 16 or 0)
- a sequence of digits
The set of valid digits for base-2 integer is 01, for base-3 integer is 012, and so on. For bases larger than 10, valid digits include alphabetic characters, starting from Aa for base-11 integer, to Zz for base-36 integer. The case of the characters is ignored.
Additional numeric formats may be accepted by the currently installed C locale.
If the value of base is 0, the numeric base is auto-detected: if the prefix is 0, the base is octal, if the prefix is 0x or 0X, the base is hexadecimal, otherwise the base is decimal.
If pos is passed a value other than 0 or nullptr, then a pointer ptr - internal to the conversion functions - will receive the address of the first unconverted character, and the index of that character will be calculated and stored in *pos.
| Contents | 
[edit] Parameters
| str | - | the string to convert | 
| pos | - | address of an integer to store the index of the first unconverted character | 
| base | - | the number base | 
[edit] Return value
The string converted to the specified signed integer 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 or if the underlying function (std::strtol or std::strtoll) sets errno to ERANGE.
[edit] Example
#include <iostream> #include <string> int main() { std::string str1 = "45"; std::string str2 = "3.14159"; std::string str3 = "31337 with words"; std::string str4 = "words and 2"; int myint1 = std::stoi(str1); int myint2 = std::stoi(str2); int myint3 = std::stoi(str3); // error: 'std::invalid_argument' // int myint4 = std::stoi(str4); std::cout << "std::stoi(\"" << str1 << "\") is " << myint1 << '\n'; std::cout << "std::stoi(\"" << str2 << "\") is " << myint2 << '\n'; std::cout << "std::stoi(\"" << str3 << "\") is " << myint3 << '\n'; //std::cout << "std::stoi(\"" << str4 << "\") is " << myint4 << '\n'; }
Output:
std::stoi("45") is 45
std::stoi("3.14159") is 3
std::stoi("31337 with words") is 31337[edit] See also
| converts a byte string to an integer value (function) | |
| (C++11)(C++11) | converts a string to an unsigned integer (function) | 
| (C++11)(C++11)(C++11) | converts a string to a floating point value (function) | 
| (C++11) | converts an integral or floating point value to string(function) | 


