list index out of range

- I have data:
```json
{
    "data": [
        {
            "name": "first",
        },
        {
            "name": "second"
        }
    ]
}
```

- template I used:
```
    data.[3].name
```

- error: `list index out of range`

- How to fix it, I don't know in advance the number of elements in the array