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json/api/basic_json/rend.md
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2026-10-27 12:14:00 +00:00

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nlohmann::basic_json::rend

reverse_iterator rend() noexcept;
const_reverse_iterator rend() const noexcept;

Returns an iterator to the reverse-end; that is, one before the first element. This element acts as a placeholder, attempting to access it results in undefined behavior.

rend rbegin Reverse past-the-last element A reverse iterator stores an iterator to the next element begin end Past-the-last element

`rend()` points to the position before the first element and `rbegin()` to the last element. The upper row is the reversed sequence and the lower row the forward sequence; dashed arrows link each reverse iterator to the forward iterator it stores, and dashed cells are past-the-last positions.

Return value

reverse iterator to the element following the last element

Exception safety

No-throw guarantee: this member function never throws exceptions.

Complexity

Constant.

Examples

??? example

The following code shows an example for `rend()`.

```cpp
#include <iostream>
#include <nlohmann/json.hpp>

using nlohmann::json;

int main()
{
    // create an array value
    json array = {1, 2, 3, 4, 5};

    // get an iterator to the reverse-end
    json::reverse_iterator it = array.rend();

    // increment the iterator to point to the first element
    --it;

    // serialize the element that the iterator points to
    std::cout << *it << '\n';
}

```

Output:

```json
1

```

See also

  • rbegin - returns a reverse iterator to the last element
  • crend - returns a const reverse iterator to one before the first element
  • end - returns an iterator to one past the last element
  • Iterators - the article on iterators

Version history

  • Added in version 1.0.0.