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std::basic_string<CharT,Traits,Allocator>::back
| (1) | ||
|
(until C++20) | |
|
(since C++20) | |
| (2) | ||
|
(until C++20) | |
|
(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
#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
|
(DR*)
|
accesses the first character (public member function) |
| accesses the last character (public member function of std::basic_string_view<CharT,Traits>) |
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