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

 

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std::basic_string

メンバ関数 basic_string::basic_string basic_string::operator= basic_string::assign basic_string::get_allocator 要素アクセス basic_string::at basic_string::operator[] basic_string::front (C++11) basic_string::back (C++11) basic_string::data basic_string::c_str basic_string::operator basic_string_view (C++17) イテレータ 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) 容量 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)

操作 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::starts_with (C++20) basic_string::ends_with (C++20) basic_string::replace basic_string::substr basic_string::copy basic_string::resize basic_string::swap 検索 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 定数 basic_string::npos

非メンバ関数 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) operator""s (C++14) ヘルパークラス hash<std::string> hash<std::wstring> hash<std::u32string> hash<std::u16string> (C++11) (C++11) (C++11) (C++11) hash<std::pmr::string> hash<std::pmr::wstring> hash<std::pmr::u32string> hash<std::pmr::u16string> (C++20) (C++20) (C++20) (C++20) 推定ガイド(C++17)

 

ヘッダ <string> で定義
int       stoi( const std::string& str, size_t *pos = 0, int base = 10 );	(1)	(C++11およびそれ以降)
long      stol( const std::string& str, size_t *pos = 0, int base = 10 );	(2)	(C++11およびそれ以降)
long long stoll( const std::string& str, size_t *pos = 0, int base = 10 );	(3)	(C++11およびそれ以降)

文字列の符号付き整数値を解釈str.

Original:

Interprets a signed integer value in the string str.

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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:

• (オプション) plus or minus sign
• (オプション) prefix (0) indicating octal base (applies only when the base is 8)
• (オプション) 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.

ない最初の文字のインデックスにposに格納されています。NULLがposとして渡された場合、それは無視される.

Original:

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

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パラメータ

str	-	変換する文字列 Original: the string to convert The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
pos	-	ない最初の文字のインデックスを格納する整数のアドレス Original: address of an integer to store the index of the first unconverted character The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
base	-	基数 Original: the number base The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

値を返します

文字列は、指定された符号付き整数型に変換.

Original:

The string converted to the specified signed integer type.

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例外

• std::invalid_argument変換が行われなかった場合

  Original:

  std::invalid_argument if no conversion could be performed

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• std::out_of_range変換された値が結果の型の範囲外に落ちるならば.

  Original:

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

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例

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

出力:

45

参照

atoi atol atoll	バイト文字列を整数値に変換します (関数)
stoul stoull (C++11) (C++11)	文字列を符号なし整数に変換します (関数)
stof stod stold (C++11) (C++11) (C++11)	文字列を浮動小数点値に変換します (関数)
to_string (C++11)	整数または浮動小数点値を string に変換します (関数)