public member function

std::string::back

      char& back();const char& back() const;

Access last character

Returns a reference to the last character of the string.

This function shall not be called on empty strings.

Parameters

none

Return value

A reference to the last character in the string.

If the string object is const-qualified, the function returns a

const char&. Otherwise, it returns a char&.

Example

// string::back
#include <iostream>
#include <string>

int main ()
{
  std::string str ("hello world.");
  str.back() = '!';
  std::cout << str << '\n';
  return 0;
}

Output:

Complexity

Constant.

Iterator validity

No changes.

Data races

The container is accessed (neither the const nor the non-const versions modify the container).
The reference returned can be used to access or modify characters. Concurrently accessing or modifying different characters is safe.

Exception safety

If the string is not empty, the function never throws exceptions (no-throw guarantee).
Otherwise, it causes undefined behavior.