# StringBuilder

`import { StringBuilder } from "destack:string";`

Mutable UTF-8 string builder with growable backing storage.

```ds title="StringBuilder"
export class StringBuilder {
    bytes: Unique<[MaybeUninit<uint8>]>;
    initializedLength: usize;
    capacity: usize;
}
```

[language/library/src/string/builder.ds:8:17](https://github.com/destack-sh/destack/blob/main/language/library/src/string/builder.ds#L8-L17)

## Members

### `bytes: Unique<[MaybeUninit<uint8>]>`

The owned UTF-8 bytes.

### `initializedLength: usize`

The initialized byte count.

### `capacity: usize`

The allocated byte capacity.