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

```cpp
using default_object_comparator_t = std::less<StringType>;  // until C++14

using default_object_comparator_t = std::less<>;            // since C++14
```

The default comparator used by [`object_t`](object_t.md).

Since C++14 a transparent comparator is used which prevents unnecessary string construction
when looking up a key in an object.

The actual comparator used depends on [`object_t`](object_t.md) and can be obtained via
[`object_comparator_t`](object_comparator_t.md).

## Examples

??? example

    The example below demonstrates the default comparator.

    ```cpp
    #include <iostream>
    #include <nlohmann/json.hpp>
    
    using nlohmann::json;
    
    int main()
    {
        std::cout << std::boolalpha
                  << "one < two : " << json::default_object_comparator_t{}("one", "two") << "\n"
                  << "three < four : " << json::default_object_comparator_t{}("three", "four") << '\n';
    }
    
    ```
    
    Output:
    
    ```json
    one < two : true
    three < four : false
    
    ```

## See also

- [`object_comparator_t`](object_comparator_t.md) - the comparator actually used by `object_t`
- [`object_t`](object_t.md) - the type used to store JSON objects
- [Template Parameter Requirements](../../features/types/template_parameters.md) - requirements on the `ObjectType` template parameter
- [Object order](../../features/object_order.md) - preserve the insertion order of keys

## Version history

- Added in version 3.11.0.