# `ARRAY_PREPEND`

**Applies to:** ✅ Data 360 SQL ✅ Tableau Hyper API

Inserts a value at the start of an array.

## Syntax

```sql
array_prepend(<value>, <array>)
```

## Arguments

### Required

- `<value>`: The value to insert at the start of the array. The value must match the array element type.
- `<array>`: The array to prepend to.

## Returns

Returns an array with the new value inserted at the beginning.

## Considerations

- Prepending NULL changes the array element type to nullable.

## Examples

### Prepend a Value

Add a value to the front of an array.

```sql
SELECT array_prepend(1, array[2, 3, 4]) AS result;
```

Returns `array[1, 2, 3, 4]`, with 1 inserted at the beginning.

### Prepend NULL

Add a NULL value to the front of an array.

```sql
SELECT array_prepend(null, array[2, 3, 4]) AS result;
```

Returns `array[null, 2, 3, 4]`. Prepending NULL to an array with a non-nullable element type changes the resulting element type to nullable.

## Related Documentation

- [Array Data Type](/docs/data/data-cloud-query-guide/references/dc-sql-reference/array.md)