# append

Inserts an element at the back of a list.

```tql
append(xs:list, x:any) -> list
```

## Description

The `append` function returns the list `xs` with `x` inserted at the end. The expression `xs.append(x)` is equivalent to `[...xs, x]`.

## Examples

### Append a number to a list

```tql
from {xs: [1, 2]}
xs = xs.append(3)
```

```tql
{xs: [1, 2, 3]}
```

## See Also

* [`add`](https://preview.docs.tenzir.com/375/375/reference/functions/add.md)
* [`concatenate`](https://preview.docs.tenzir.com/375/375/reference/functions/concatenate.md)
* [`prepend`](https://preview.docs.tenzir.com/375/375/reference/functions/prepend.md)
* [`remove`](https://preview.docs.tenzir.com/375/375/reference/functions/remove.md)
* [Shape lists](https://preview.docs.tenzir.com/375/375/guides/transformation/shape-lists.md)