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

# Array: Fill with value

> Creates an array filled with a repeated value at the specified length.

export const FormField = ({property, label, required = false, diType, uiPatterns, children}) => {
  const patterns = Array.isArray(uiPatterns) ? uiPatterns : uiPatterns ? [uiPatterns] : [];
  return <div style={{
    margin: '1.5rem 0'
  }}>
      <div style={{
    display: 'flex',
    alignItems: 'baseline',
    flexWrap: 'wrap',
    gap: '0.5rem',
    marginBottom: '0.25rem'
  }}>
        <strong>{label}</strong>
        <span style={{
    fontSize: '0.7rem',
    fontWeight: 600,
    textTransform: 'uppercase',
    letterSpacing: '0.04em',
    color: required ? '#6241f5' : '#6b7280'
  }}>
          {required ? 'Required' : 'Optional'}
        </span>
      </div>

      <div>{children}</div>

      {diType || patterns.length > 0 ? <p style={{
    fontSize: '0.85rem',
    color: '#6b7280',
    marginBottom: 0
  }}>
          {diType ? <>
              See the <a href={`/references/${diType}`}>{diType}</a> reference.{' '}
            </> : null}
          {patterns.length > 0 ? <>
              Accepts a <a href={`/documentation/placeholders-and-patterns/patterns#${patterns[0]}`}>pattern</a>.
            </> : null}
        </p> : null}
    </div>;
};

Use this mapper to build a new list by repeating the input value a fixed number of times. The value it receives becomes the value that fills every slot, and you choose how many slots there are and at which position the list starts counting. This is useful when a target system expects a list of a known length, or when you need to repeat a placeholder value a set number of times.

This documentation describes: [Schema](/schemas/mapper/list-fill)

## Fields

<FormField property="start" label="Start">
  The position the first item is numbered from. Defaults to `0`, which gives a normal list starting at the first position. Set a higher number if the target expects the list to begin counting elsewhere; the result then becomes a keyed object starting from that position.
</FormField>

<FormField property="length" label="Length" required>
  How many times the input value is repeated, in other words how many items the resulting list has.
</FormField>

## Sample data

This example repeats an incoming status value three times.

| Field  | Value |
| ------ | ----- |
| Start  | `0`   |
| Length | `3`   |

Input:

```json theme={null}
"pending"
```

Output:

```json theme={null}
["pending", "pending", "pending"]
```

With Start set to `2` instead, the same input produces a keyed object numbered from that position: `{ "2": "pending", "3": "pending", "4": "pending" }`.

```json Configuration theme={null}
{
  "prototype": "list-fill",
  "parameters": {
    "start": 0,
    "length": "3"
  }
}
```