# forward

[Built-ins](README.md)

Canonical ID: `turtle.forward`. Nederlands: `vooruit`.

Moves the turtle by a signed distance along its current heading. A positive distance goes forward and a negative one backward. Movement draws only when the pen is down. The initial turtle is centered and faces up. No separate backward function is needed.

## Signature

```text
forward(distance)
```

## Arguments

| Parameter | Type | Requirement |
|---|---|---|
| `distance` | Number | Finite signed distance in turtle scene units. |

## Return value

`None`.

## Example

```pliro
# language: en
forward(80)
right(90)
forward(-40)
```

Draws forward, turns, then moves backward along the new heading.

## Notes and common mistakes

Use the function name for your source language. Its [canonical ID](../concepts/canonical-identity.md) is a shared documentation label; you do not type that ID as a call. Giving your own variable or function the same name can hide the built-in. Supply the documented [arguments](../concepts/parameters-and-arguments.md) and value types. Pliro reports mismatches when checking can detect them, or when the call runs.

A **host** is the app or environment running your program. To see a drawing, it needs a **renderer**, the part that draws on screen. The [command-line](../concepts/command-line.md) command `pliro run` shows text but does not draw these graphics. The [host support table](../guides/hosts.md) explains which effects work in the IDE, browser, native app, and phone preview. A native build reports an unsupported capability instead of leaving it out.

The initial turtle is centered, facing up, with its pen down. State can persist between explicit [IDE](../concepts/ide.md) runs; Reset Scene restores it. Portable compositing with immediate scene graphics is not yet specified, so use a consistent drawing mode when comparing hosts.

## Related entries

[right](right.md) · [left](left.md) · [penUp](penUp.md) · [penDown](penDown.md) · [clear](clear.md) · [Programming guides](../guides/turtle.md) · [Host support](../guides/hosts.md) · [Calls and arguments](../syntax/calls.md)