json/api/basic_json/rbegin.md

# <small>nlohmann::basic_json::</small>rbegin

```cpp
reverse_iterator rbegin() noexcept;
const_reverse_iterator rbegin() const noexcept;
```

Returns an iterator to the reverse-beginning; that is, the last element.

<div class="nj-fig-wrap" markdown>
<svg class="nj-fig nj-fig--range" viewBox="0 0 600 236" role="img" aria-labelledby="fig-rbe-title" xmlns="http://www.w3.org/2000/svg">
<title id="fig-rbe-title">Two rows of sixteen cells. The upper row shows the reversed sequence: rend() points to a dashed position before the first element and rbegin() to the last element. The lower row shows the forward sequence: begin() points to the first element and end() to a dashed position after the last element. A reverse iterator stores an iterator to the next element, so rend() corresponds to begin() and rbegin() to end().</title>
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<text class="fg-note fg-note--l" x="81" y="24">Reverse past-the-last element</text>
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</svg>

</div>

<p class="nj-caption" markdown>`rbegin()` points to the last element and `rend()` to the position before the first
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.</p>

## Return value

reverse iterator to 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 `rbegin()`.
    
    ```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-beginning
        json::reverse_iterator it = array.rbegin();
    
        // serialize the element that the iterator points to
        std::cout << *it << '\n';
    }
    
    ```
    
    Output:
    
    ```json
    5
    
    ```

## See also

- [`rend`](rend.md) - returns a reverse iterator to one before the first element
- [`crbegin`](crbegin.md) - returns a const reverse iterator to the last element
- [`begin`](begin.md) - returns an iterator to the first element
- [Iterators](../../features/iterators.md) - the article on iterators

## Version history

- Added in version 1.0.0.