本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# $radiansToDegrees
<a name="radiansToDegrees"></a>

8.0.1 版的新功能。

Amazon DocumentDB 中的`$radiansToDegrees`運算子會將值從弧度轉換為度數。

**參數**
+ `expression`：解析為弧度數值的表達式。

## 範例 (MongoDB Shell)
<a name="radiansToDegrees-examples"></a>

下列範例示範如何使用 `$radiansToDegrees`運算子將弧度值轉換為度數。

**建立範例文件**

```
db.angles.insertMany([
  { "_id": 1, "radians": 0 },
  { "_id": 2, "radians": 1.5707963267948966 },
  { "_id": 3, "radians": 3.141592653589793 },
  { "_id": 4, "radians": 6.283185307179586 }
]);
```

**查詢範例**

```
db.angles.aggregate([
  { $project: {
    "degrees": { $radiansToDegrees: "$radians" }
  }}
]);
```

**輸出**

```
[
  { "_id": 1, "degrees": 0 },
  { "_id": 2, "degrees": 90 },
  { "_id": 3, "degrees": 180 },
  { "_id": 4, "degrees": 360 }
]
```

## 程式碼範例
<a name="radiansToDegrees-code"></a>

若要檢視使用 `$radiansToDegrees` 運算子的程式碼範例，請選擇您要使用的語言標籤：

------
#### [ Node.js ]

```
const { MongoClient } = require('mongodb');

async function main() {
  const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
  const db = client.db('test');
  const collection = db.collection('angles');

  const result = await collection.aggregate([
    { $project: {
      "degrees": { $radiansToDegrees: "$radians" }
    }}
  ]).toArray();

  console.log(result);
  await client.close();
}

main();
```

------
#### [ Python ]

```
from pymongo import MongoClient

def main():
    client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
    db = client['test']
    collection = db['angles']

    result = list(collection.aggregate([
        { '$project': {
            'degrees': { '$radiansToDegrees': '$radians' }
        }}
    ]))

    print(result)
    client.close()

if __name__ == "__main__":
    main()
```

------