# ByteArrayOutputStream constructor

ByteArrayOutputStream([

1. int initialCapacity = _defaultInitialCapacity

])

An OutputStream that writes to a growable internal byte buffer.

`ByteArrayOutputStream` provides an in-memory output sink similar to Java's `ByteArrayOutputStream`. It allows binary data to be written sequentially and later retrieved as a single Uint8List for processing, storage, or transmission.

This stream grows automatically as more bytes are written, making it suitable for dynamic or unknown-length binary outputs.

### 🔧 Example:

    final stream = ByteArrayOutputStream();
    stream.writeByte(104); // h
    stream.writeByte(105); // i

    final result = stream.toBytes();
    print(String.fromCharCodes(result)); // hi

### ✅ Use Cases:

- Buffering binary content before sending to a file or network.
- Serializing data in memory.
- Mocking writable streams during testing.

Creates a new ByteArrayOutputStream with an optional `initialCapacity`. If not provided, defaults to `32` bytes.

The internal buffer will automatically grow when needed.

## Implementation

    ByteArrayOutputStream([int initialCapacity = _defaultInitialCapacity])
        : _buffer = Uint8List(initialCapacity);