std::stoi, std::stol, std::stoll

 

C++

Language

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Strings library

Null-terminated strings

Byte strings

Multibyte strings

Wide strings

Classes

basic_string

char_traits

 

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

operator+

operator== operator!= operator< operator> operator<= operator>=

swap(std::basic_string)

operator<< operator>>

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)

Helper classes

hash<std::string> hash<std::wstring> hash<std::u32string> hash<std::u16string> (C++11)

 

Defined in header <string>
int       stoi( const std::string& str, size_t *pos = 0, int base = 10 );	(1)	(since C++11)
long      stol( const std::string& str, size_t *pos = 0, int base = 10 );	(2)	(since C++11)
long long stoll( const std::string& str, 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 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)
• (optional) prefix (0x or 0X) indicating hexadecimal base (applies only when the base is 16)
• 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.

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

Parameters

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

Return value

The string converted to the specified signed integer type.

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.

Example

#include <iostream>
#include <string>
 
int main()
{
    std::string test = "45";
    int myint = stoi(test);
    std::cout << myint << '\n';
}

Output:

45

See also

stoul stoull (C++11) (C++11)	converts a string to an unsigned integer (function)
stof stod stold (C++11) (C++11) (C++11)	converts a string to an floating point value (function)