std::basic_string<CharT,Traits,Allocator>::back

 

C++

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自立与有宿主实现

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概念库 (C++20)

诊断库

工具库

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正则表达式库 (C++11)

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技术规范

 

字符串库

空终止字符串

字节字符串

多字节字符串

宽字符串

类

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string

成员函数 basic_string::basic_string basic_string::operator= basic_string::assign basic_string::get_allocator 元素访问 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) 迭代器 basic_string::beginbasic_string::cbegin (C++11) basic_string::endbasic_string::cend (C++11) basic_string::rbeginbasic_string::crbegin (C++11) basic_string::rendbasic_string::crend (C++11) 容量 basic_string::empty basic_string::sizebasic_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::contains (C++23) basic_string::replace basic_string::substr basic_string::copy basic_string::resize basic_string::resize_and_overwrite (C++23) basic_string::swap

搜索 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 常量 basic_string::npos 推导指引 (C++17) 非成员函数 operator+ swap(std::basic_string) operator""s (C++14) erase(std::basic_string)erase_if(std::basic_string) (C++20)(C++20) I/O operator<<operator>> getline 比较 operator==operator!=operator<operator>operator<=operator>=operator<=> (C++20 前)(C++20 前)(C++20 前)(C++20 前)(C++20 前)(C++20) 数值转换 stoistolstoll (C++11)(C++11)(C++11) stoulstoull (C++11)(C++11) stofstodstold (C++11)(C++11)(C++11) to_string (C++11) to_wstring (C++11) 辅助类 hash<std::string>hash<std::wstring>hash<std::u32string>hash<std::u16string>hash<std::u8string> (C++11)  (C++11)(C++11)(C++11)(C++20) hash<std::pmr::string>hash<std::pmr::wstring>hash<std::pmr::u32string>hash<std::pmr::u16string>hash<std::pmr::u8string> (C++17)(C++17)(C++17)(C++17)(C++20)

 

CharT& back();		(C++11 起) (C++20 前)
constexpr CharT& back();		(C++20 起)
const CharT& back() const;		(C++11 起) (C++20 前)
constexpr const CharT& back() const;		(C++20 起)

返回字符串中的末字符。若 empty() == true 则行为未定义。

参数

（无）

返回值

到末字符的引用，等价于 operator[](size() - 1) 。

复杂度

常数

示例

运行此代码

#include <iostream>
#include <string>
 
int main()
{
  {
    std::string s("Exemplary");
    char& back = s.back();
    back = 's';
    std::cout << s << '\n'; // "Exemplars"
  }
 
  {
    std::string const c("Exemplary");
    char const& back = c.back();
    std::cout << back << '\n'; // 'y'
  }
}

输出：

Exemplars
y

参阅

front (C++11)

访问首字符 (公开成员函数)