std::basic_string<CharT,Traits,Allocator>::back
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< cpp | string | basic string
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(C++17)
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std::basic_string
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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 |
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| LWG 534 | C++98 | std::basic_string did not have the member function back()
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added |
See also
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(DR*)
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accesses the first character (public member function) |
| accesses the last character (public member function of std::basic_string_view<CharT,Traits>) |