std::basic_string<CharT,Traits,Allocator>:: operator[]

Returns a reference to the character at specified location pos if pos < size ( ) , or a reference to CharT ( ) if pos == size ( ) . No bounds checking is performed.

If pos > size ( ) , the behavior is undefined.

For overload (1) , if pos == size ( ) , the behavior is undefined if the object referred by the returned reference is modified to any value other than CharT ( ) (since C++11) .

Parameters

Return value

* ( begin ( ) + pos ) if pos < size ( ) , or a reference to CharT ( ) if pos == size ( ) .

Complexity

Constant.

Example

#include <iostream>
#include <string>
 
int main()
{
    const std::string e("Exemplar");
    for (unsigned i = e.length() - 1; i != 0; i /= 2)
        std::cout << e[i];
    std::cout << '\n';
 
    const char* c = &e[0];
    std::cout << c << '\n'; // print as a C string
 
    // Change the last character of s into a 'y'
    std::string s("Exemplar ");
    s[s.size() - 1] = 'y'; // equivalent to s.back() = 'y';
    std::cout << s << '\n';
}

rmx
Exemplar
Exemplary

Defect reports

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

See also