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

```cpp
using object_comparator_t = typename object_t::key_compare;
// or
using object_comparator_t = default_object_comparator_t;
```

The comparator used by [`object_t`](object_t.md). Defined as `#!cpp typename object_t::key_compare` if available,
and [`default_object_comparator_t`](default_object_comparator_t.md) otherwise.

## Examples

??? example

    The example below demonstrates the used object comparator.

    ```cpp
    --8<-- "examples/object_comparator_t.cpp"
    ```
    
    Output:
    
    ```json
    --8<-- "examples/object_comparator_t.output"
    ```

## Version history

- Added in version 3.0.0.
- Changed to be conditionally defined as `#!cpp typename object_t::key_compare` or `default_object_comparator_t` in
  version 3.11.0.
- Fixed the fallback to `default_object_comparator_t`, which previously failed to compile for object types without a
  `key_compare` member type, in version 3.13.0.
