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

 

C++

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Named requirements

Feature test macros (C++20)

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Concepts library (C++20)

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Technical specifications

Symbols index

External libraries

 

Strings library

Null-terminated strings

Byte strings

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Classes

basic_string

basic_string_view (C++17)

char_traits

 

std::basic_string

Member functions basic_string::basic_string basic_string::~basic_string basic_string::operator= basic_string::assign basic_string::assign_range (C++23) basic_string::get_allocator Element access basic_string::at basic_string::operator[] basic_string::front (DR*) basic_string::back (DR*) basic_string::data basic_string::c_str basic_string::operator  basic_string_view (C++17) Iterators 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) Capacity basic_string::empty basic_string::sizebasic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (DR*) Modifiers basic_string::clear basic_string::insert basic_string::insert_range (C++23) basic_string::erase basic_string::push_back basic_string::pop_back (DR*) basic_string::append basic_string::append_range (C++23) basic_string::operator+= basic_string::replace basic_string::replace_with_range (C++23) basic_string::copy basic_string::resize basic_string::resize_and_overwrite (C++23)   basic_string::swap

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CharT& back();	(1)	(constexpr since C++20)
const CharT& back() const;	(2)	(constexpr since C++20)

Returns reference to the last character in the string. The behavior is undefined if empty() is true.

Parameters

(none)

Return value

Reference to the last character, equivalent to operator[](size() - 1).

Complexity

Constant.

Notes

In libstdc++, back() is not available in C++98 mode.

Example

Run this code

#include <iostream>
#include <string>
 
int main()
{
    std::string s("Exemplary");
    char& back1 = s.back();
    back1 = 's';
    std::cout << s << '\n'; // "Exemplars"
 
    std::string const c("Exemplary");
    char const& back2 = c.back();
    std::cout << back2 << '\n'; // 'y'
}

Output:

Exemplars
y

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 534	C++98	std::basic_string did not have the member function back()	added

See also

front (DR*)	accesses the first character (public member function)
back	accesses the last character (public member function of std::basic_string_view<CharT,Traits>)