map.put(1, "a");
    map.put(4, "b");
    map.put(3, "d");
    map.put(2, "c");
    map.trimToSize();
    assertThat(map.entries).hasLength(4);
    assertThat(map.keys).hasLength(4);
    assertThat(map.values).hasLength(4);
    assertThat(map.links).hasLength(4);
    assertEquals(4, map.size());
    testHasMapEntriesInOrder(map, 1, "a", 4, "b", 3, "d", 2, "c");
  }

          "$ref": "#/definitions/breakingArea"
        },
        "title": {
          "type": "string",
          "minLength": 1
        },
        "details": {
          "type": "string",
          "minLength": 1
        },
        "impact": {
          "type": "string",
          "minLength": 1
        },
        "notable": {
          "type": "boolean"
        }
      },
      "required": [

    for (int i = 0; i < 10; i++) {
      map.put(i, Integer.toString(i));
    }
    map.trimToSize();
    assertThat(map.entries).hasLength(10);
    assertThat(map.keys).hasLength(10);
    assertThat(map.values).hasLength(10);
    assertEquals(10, map.size());
    for (int i = 0; i < 10; i++) {
      assertThat(map.get(i)).isEqualTo(Integer.toString(i));
    }
  }

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

Varsayılan değerin hâlâ `None` olduğuna dikkat edin; yani parametre hâlâ opsiyonel.

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    q: str | None = Query(
        default=None, min_length=3, max_length=50, pattern="^fixedquery$"
    ),
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

既然我們有可以放更多資訊的 `Annotated`（在此是額外驗證），就把 `Query` 放進 `Annotated`，並把參數 `max_length` 設為 `50`：

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

注意預設值仍然是 `None`，所以這個參數仍是可選。

不過，現在在 `Annotated` 裡有 `Query(max_length=50)`，我們就告訴 FastAPI 要對這個值做「額外驗證」，最多 50 個字元即可。😎

/// tip | 提示

    assertThat(set.needsAllocArrays()).isTrue();
    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {
    for (int i = 0; i <= CompactHashing.DEFAULT_SIZE; i++) {
      CompactHashSet<Integer> set = CompactHashSet.createWithExpectedSize(i);

{* ../../docs_src/query_params_str_validations/tutorial002_an_py310.py hl[9] *}

Notice that the default value is still `None`, so the parameter is still optional.

        Query(
            alias="item-query",
            title="Query string",
            description="Query string for the items to search in the database that have a good match",
            min_length=3,
            max_length=50,
            pattern="^fixedquery$",
            deprecated=True,
        ),
    ] = None,
):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from pydantic import BaseModel, Field

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = Field(
        default=None, title="The description of the item", max_length=300
    )
    price: float = Field(gt=0, description="The price must be greater than zero")
    tax: float | None = None


@app.put("/items/{item_id}")