## Pydantic { #pydantic }

All the data validation is performed under the hood by [Pydantic](https://docs.pydantic.dev/), so you get all the benefits from it. And you know you are in good hands.

You can use the same type declarations with `str`, `float`, `bool` and many other complex data types.

Several of these are explored in the next chapters of the tutorial.

## Order matters { #order-matters }

      @Override
      public @Nullable Object[] toArray() {
        return ObjectArrays.toArrayImpl(this);
      }

      @Override
      @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
      public <T extends @Nullable Object> T[] toArray(T[] a) {
        return ObjectArrays.toArrayImpl(this, a);
      }

      @Override
      public Spliterator<K> spliterator() {

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.Nullable;

/**
 * Parses and evaluates version ranges encountered in dependency declarations.
 *
 * @since 4.0.0
 */
@Experimental
@Consumer
public interface VersionRangeResolver extends Service {

    /**
     * Expands a version range to a list of matching versions, in ascending order.

        "sec:controlling_dependency_caching_programmatically",
        "sec:offline-mode",
        "sec:controlling_dependency_caching_command_line",
        "sec:dynamic_versions_and_changing_modules",
        "single-version-declarations",
        "version_ordering",
        "sec:declaring_without_version",
        "rich-version-constraints",
        "dependency_management_in_gradle",
        "sec:dependency-mgmt-in-gradle"
    ));

            }
        }

        /*
         * NOTE: This is primarily to keep backward-compat with Maven 2.x which did not validate that dependencies are
         * unique within a single POM. Upon multiple declarations, 2.x just kept the last one but retained the order of
         * the first occurrence. So when we're in lenient/compat mode, we have to deal with such broken POMs and mimic

  }

  @Override
  public @Nullable Object[] toArray() {
    return standardToArray();
  }

  @Override
  @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
  public <T extends @Nullable Object> T[] toArray(T[] array) {
    return standardToArray(array);
  }

  @Override
  public String toString() {
    return entrySet().toString();
  }

            } catch (ClassCastException e) {
              return false;
            }
          }

          @Override
          @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
          public <T extends @Nullable Object> T[] toArray(T[] array) {
            T[] result = super.toArray(array);
            if (size() < result.length) {

**FastAPI** gives you the following:

### Based on open standards { #based-on-open-standards }

* [**OpenAPI**](https://github.com/OAI/OpenAPI-Specification) for API creation, including declarations of <dfn title="also known as: endpoints, routes">path</dfn> <dfn title="also known as HTTP methods, as POST, GET, PUT, DELETE">operations</dfn>, parameters, request bodies, security, etc.

   */

  @Override
  public Object[] toArray() {
    return snapshotElementsToList().toArray();
  }

  @Override
  @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
  public <T extends @Nullable Object> T[] toArray(T[] array) {
    return snapshotElementsToList().toArray(array);
  }

  /*
   * We'd love to use 'new ArrayList(this)' or 'list.addAll(this)', but

But you can re-order them, and have the value without a default (the query parameter `q`) first.

It doesn't matter for **FastAPI**. It will detect the parameters by their names, types and default declarations (`Query`, `Path`, etc), it doesn't care about the order.

So, you can declare your function as:

{* ../../docs_src/path_params_numeric_validations/tutorial002_py310.py hl[7] *}