> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apinizer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Adding New Key Expression and Removing Existing Key Expression

> You can add new key expressions to JSON data and remove existing key expressions. This page includes an example of adding and removing keys using remove and default operations together.

**Input Value**

```json theme={null}
{
  "Rating": 1,
  "SecondaryRatings": {
    "Design": 4,
    "Price": 2,
    "RatingDimension3": 1
  }
}
```

**JOLT Transformation Code**

<Tip>
  In this example, first the `Rating` field is removed with `remove` operation, then the `NewlyAddedField` field is added with `default` operation.
</Tip>

```json theme={null}
[
  {
    "operation": "remove",
    "spec": {
      "Rating": ""
    }
  },
  {
    "operation": "default",
    "spec": {
      "NewlyAddedField": "123"
    }
  }
]
```

**Output Value**

```json theme={null}
{
  "SecondaryRatings" : {
    "Design" : 4,
    "Price" : 2,
    "RatingDimension3" : 1
  },
  "NewlyAddedField" : "123"
}
```