> ## 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.

# Converting String Type Key Values to Numeric Data Type

> You can convert string type key values to numeric data type. This page includes an example of converting string values to Long type using modify-overwrite-beta operation with toLong function.

**Input Value**

```json theme={null}
{
  "kisiId": "123",
  "uyeId": "456",
  "adi": "xxx",
  "soyadi": "yyy"
}
```

**JOLT Transformation Code**

<Tip>
  The `=toLong` expression converts string values to Long type. If the value is not a valid number, an error may occur.
</Tip>

```json theme={null}
[
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "kisiId": "=toLong",
      "uyeId": "=toLong"
    }
  }
]
```

**Output Value**

```json theme={null}
{
  "kisiId": 123,
  "uyeId": 456,
  "adi": "xxx",
  "soyadi": "yyy"
}
```