```

因为上述数据未包含已存储的属性 `"tax": 20.2`，新的输入模型会把 `"tax": 10.5` 作为默认值。

因此，本次操作把 `tax` 的值「更新」为 `10.5`。

## 用 `PATCH` 进行部分更新

<a href="https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Methods/PATCH" class="external-link" target="_blank">HTTP `PATCH`</a> 操作用于更新 *部分* 数据。

即，只发送要更新的数据，其余数据保持不变。

/// note | 笔记

`PATCH` 没有 `PUT` 知名，也怎么不常用。

很多人甚至只用 `PUT` 实现部分更新。

**FastAPI** 对此没有任何限制，可以**随意**互换使用这两种操作。

    CountDownLatch latch = new CountDownLatch(1);
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/260137033
          @Override
          protected void finalize() {
            latch.countDown();
          }
        };
    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.await(latch);
    assertEquals(0, latch.getCount());
  }

 * sets of related domain names. The following forms are permitted:
 *
 *  * **Full domain name**: you may pin an exact domain name like `www.publicobject.com`. It won't
 *    match additional prefixes (`us-west.www.publicobject.com`) or suffixes (`publicobject.com`).
 *
 *  * **Any number of subdomains**: Use two asterisks to like `**.publicobject.com` to match any

                        }
                    }
                } else {
                    value = ReflectionValueExtractor.evaluate(expression, session);
                }
            } catch (Exception e) {
                // TODO don't catch exception
                throw new ExpressionEvaluationException(
                        "Error evaluating plugin parameter expression: " + expression, e);
            }

    checkNotNull(callable);
    checkNotNull(timeoutUnit);
    try {
      return callable.call();
    } catch (RuntimeException e) {
      throw new UncheckedExecutionException(e);
    } catch (Exception e) {
      restoreInterruptIfIsInterruptedException(e);
      throw new ExecutionException(e);
    } catch (Error e) {
      throw new ExecutionError(e);
    }
  }

    Object[] actual = getList().toArray();
    assertArrayEquals("toArray() order should match list", createOrderedArray(), actual);
  }

  @CollectionSize.Require(absent = ZERO)
  public void testToArray_tooSmall() {
    Object[] actual = getList().toArray(new Object[0]);
    assertArrayEquals("toArray(tooSmall) order should match list", createOrderedArray(), actual);
  }

  public void testToArray_largeEnough() {

        }
        return "https://golang.org/cl/" + t;
    }

    if (gerritChangeIdRE.test(t)) {
        return "https://golang.org/cl/" + t;
    }

    var match = commitRE.exec(t);
    if (match) {
        return "https://golang.org/change/" + match[1];
    }

    if (pkgRE.test(t)) {
        // TODO: make this smarter, using a list of packages + substring matches.
        // Get the list from godoc itself in JSON format?

                try {
                    zos.write(data.getBytes(Constants.CHARSET_UTF_8));
                } catch (final IOException e) {
                    logger.warn("Failed to access /{}/{}.", index, hit.getId(), e);
                }
                return true;
            });
        } catch (final IOException e) {
            logger.warn("Failed to access /{}.", index, e);
        }
    }

    /**

Und die Daten würden mit diesem „neuen“ `tax` von `10.5` gespeichert werden.

## Teil-Aktualisierungen mit `PATCH` { #partial-updates-with-patch }

Sie können auch die <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/PATCH" class="external-link" target="_blank">HTTP `PATCH`</a> Operation verwenden, um Daten *teilweise* zu ersetzen.

                fos = null; // Successfully wrapped, no need to close explicitly
            } catch (final Exception e) {
                if (fos != null) {
                    try {
                        fos.close();
                    } catch (final IOException ioe) {
                        // Ignore close exception
                    }
                }