# deleteData

[Built-ins](README.md)

Canonical ID: `storage.delete`. Nederlands: `verwijderGegeven`.

Removes one app-private key and returns true only if that key existed. Deleting a missing key returns false and is harmless. The key is still validated even when absent. This operation removes saved data, not a project asset or a host file.

## Signature

```text
deleteData(key)
```

## Arguments

| Parameter | Type | Requirement |
|---|---|---|
| `key` | Text | Nonempty, no surrounding whitespace/control characters, at most 128 [UTF-8](../concepts/utf-8.md) bytes. |

## Return value

`Boolean`.

## Example

```pliro
# language: en
saveData("temporary", 12)
say deleteData("temporary")
say deleteData("temporary")
```

Prints `true` then `false`.

## 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.

Keys and saved text are not translated. Limits are 128 keys, 64 KiB per [JSON](../concepts/json.md) value, 512 KiB per document, 32 nesting levels, and 8,192 values/nodes per value. Functions, nonfinite numbers, and Maps with non-Text keys cannot be stored. A usable portable project identity enables durable data; loose source uses temporary session storage. See the storage guide for E4014–E4017 and copy/identity rules.

## Related entries

[saveData](saveData.md) · [loadData](loadData.md) · [savedDataKeys](savedDataKeys.md) · [Programming guides](../guides/storage.md) · [Host support](../guides/hosts.md) · [Calls and arguments](../syntax/calls.md)