std::string end() method

since C++20

// Non-const version
constexpr iterator end() noexcept;

// Const version
constexpr const_iterator end() const noexcept;
constexpr const_iterator cend() const noexcept;

since C++11

// Non-const version
iterator end() noexcept;

// Const version
const_iterator end() const noexcept;
const_iterator cend() const noexcept;

until C++11

// Non-const version
iterator end();

// Const version
const_iterator end() const;

Returns an iterator

to the element past-the-end of the array.
If the array is empty, the returned iterator will be equal to begin().

Attempting to dereference a past-the-end iterator is undefined behaviour

.

Parameters

(none)

Return value

Iterator to the character following the last character

Complexity

Constant - O(1)..

Notes

For a container c, the expression *c.begin() is equivalent to c.front().

Difference between end and cend

For a const container c, end and cend are the same - c.end() == c.cend()

For non-const container of type c they return different iterators:

Non const container

end

#include <string>

int main()
{
    std::string str = "Hello";
    auto it = str.end(); // Type: std::string::iterator
    *std::prev(it) = 'J'; // ✔ Ok
}

cend

#include <string>

int main()
{
    std::string str = "Hello";
    auto it = str.cend(); // Type: std::string::const_iterator
    *std::prev(it) = 'J'; // ❌ Error! 
}

Const container

end

#include <string>

int main()
{
    const std::string str = "Hello";
    auto it = str.end(); // Type: std::string::const_iterator
    *std::prev(it) = 'J'; // ❌ Error! 
}

cend

#include <string>

int main()
{
    const std::string str = "Hello";
    auto it = str.cend(); // Type: std::string::const_iterator
    *std::prev(it) = 'J'; // ❌ Error! 
}

Example

Main.cpp

#include <iostream>
#include <algorithm>
#include <iterator>
#include <string>
 
int main()
{
    std::string s("Exemparl");
    std::next_permutation(s.begin(), s.end());
 
    std::string c;
    std::copy(s.cbegin(), s.cend(), std::back_inserter(c));
    std::cout << c <<'\n'; // "Exemplar"
}

Output

Exemplar