# FLATTEN

### Description

`FLATTEN` extracts either one or more keys from a dictionary. When extracting only one key the result is a list, when extracting multiple the result is a list of dictionaries

### Example 1

```
FLATTEN(
  [
    {"key": "a", "name": "Thorben"},
    {"key": "b", "name": "Peter"},
    {"key": "c", "name": "Karin"},
    {"key": "d", "name": "Karl"},
  ],
  'key',
)
```

This returns a list of just the keys, so in this case `['a', 'b', 'c', 'd']`

### Example 2

```
FLATTEN(
  [
    {"key": "a", "name": "Karl", "age": 36},
    {"key": "b", "name": "Peter", "age": 26},
    {"key": "c", "name": "Karin", "age": 31},
  ],
  ["key", "name"]
)
```

This returns a list of dictionaries with just the mentioned the keys, so in this case

```
[
    {"key": "a", "name": "Karl"},
    {"key": "b", "name": "Peter"},
    {"key": "c", "name": "Karin"},
]
```

###