//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// 你可以使用以下指令建立一個名為 MY_NAME 的環境變數
$ export MY_NAME="Wade Wilson"

// 然後，你可以在其他程式中使用它，例如
$ echo "Hello $MY_NAME"

Hello Wade Wilson
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

```console
// 建立一個名為 MY_NAME 的環境變數
$ $Env:MY_NAME = "Wade Wilson"

/**
 * <p>
 *   Deferred is a class that represents a deferred computation.
 *   It is similar to a Promise in JavaScript.
 *   It allows you to register callbacks that will be executed when the computation is complete,
 *   either successfully (resolve) or with an error (reject).
 * </p>
 *
 * <p>
 *   The Deferred class has a Promise inner class that allows you to register callbacks

    Set<Entry<K, V>> es = entrySet;
    return (es != null) ? es : (entrySet = new EntrySet(this));
  }

  /**
   * Custom Entry class used by EntryIterator.next(), that relays setValue changes to the underlying
   * map.
   */
  private final class WriteThroughEntry implements Entry<K, V> {
    final K key;
    V value;

    WriteThroughEntry(K key, V value) {
      this.key = checkNotNull(key);

`int`가 아닌 `float`을 전달하는 경우에도 동일한 오류가 나타납니다: <a href="http://127.0.0.1:8000/items/4.2" class="external-link" target="_blank">http://127.0.0.1:8000/items/4.2</a>

/// check | 확인

즉, 파이썬 타입 선언을 하면 **FastAPI**는 데이터 검증을 합니다.

오류에는 정확히 어느 지점에서 검증을 통과하지 못했는지 명시됩니다.

이는 API와 상호 작용하는 코드를 개발하고 디버깅하는 데 매우 유용합니다.

///

## 문서화

### 查看它

在瀏覽器中打開 <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

你將看到如下的 JSON 回應：

```JSON
{"message": "Hello World"}
```

### 互動式 API 文件

現在，前往 <a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>.

你將看到自動的互動式 API 文件（由 <a href="https://github.com/swagger-api/swagger-ui" class="external-link" target="_blank">Swagger UI</a> 提供）：

 *
 * As bytes are returned from upstream they are written to a local file. Downstream sources read
 * from this file as necessary.
 *
 * This class also keeps a small buffer of bytes recently read from upstream. This is intended to
 * save a small amount of file I/O and data copying.
 */
class Relay private constructor(
  /**
   * Read/write persistence of the upstream source and its metadata. Its layout is as follows:
   *

 */
@GwtCompatible
@NullMarked
public class ImmutableSetTest extends AbstractImmutableSetTest {

  @J2ktIncompatible
  @GwtIncompatible // suite
  @AndroidIncompatible // test-suite builders
  public static Test suite() {
    TestSuite suite = new TestSuite();

    suite.addTest(
        SetTestSuiteBuilder.using(new ImmutableSetCopyOfGenerator())
            .named(ImmutableSetTest.class.getName())
            .withFeatures(

import static org.junit.Assert.assertTrue;

import java.util.Set;
import org.jspecify.annotations.NullUnmarked;
import org.junit.Test;

/**
 * Abstract base class for testing directed {@link Graph} implementations defined in this package.
 */
@NullUnmarked
public abstract class AbstractStandardDirectedGraphTest extends AbstractGraphTest {

  @Override
  @Test
  public void nodes_checkReturnedSetMutability() {

        void shouldImplementAllocInfo() {
            assertTrue(AllocInfo.class.isAssignableFrom(FileFsFullSizeInformation.class));
        }

        @Test
        @DisplayName("Should implement FileSystemInformation interface")
        void shouldImplementFileSystemInformation() {
            assertTrue(FileSystemInformation.class.isAssignableFrom(FileFsFullSizeInformation.class));
        }

        @Test

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterEntries(Multimap, Predicate)}.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible
class FilteredEntryMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMultimap<K, V> implements FilteredMultimap<K, V> {
  final Multimap<K, V> unfiltered;
  final Predicate<? super Entry<K, V>> predicate;