ByteArray

Package	flash.utils
Class	public class ByteArray
Inheritance	ByteArray Object
Implements	IDataInput, IDataOutput
Subclasses	ByteArrayAsset

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

The ByteArray class provides methods and properties to optimize reading, writing, and working with binary data.

Note: The ByteArray class is for advanced developers who need to access data on the byte level.

In-memory data is a packed array (the most compact representation for the data type) of bytes, but an instance of the ByteArray class can be manipulated with the standard [] (array access) operators. It also can be read and written to as an in-memory file, using methods similar to those in the URLStream and Socket classes.

In addition, zlib, deflate, and lzma compression and decompression are supported, as well as Action Message Format (AMF) object serialization.

A ByteArray object can share its backing memory among multiple worker instances by setting its shareable property to true.

Possible uses of the ByteArray class include the following:

Creating a custom protocol to connect to a server.
Writing your own URLEncoder/URLDecoder.
Writing your own AMF/Remoting packet.
Optimizing the size of your data by using data types.
Working with binary data loaded from a file.

View the examples

More examples

Working with byte arrays
Reading and writing a ByteArray
ByteArray example: Reading a .zip file

Related API Elements

[] (array access)
Socket class
URLStream class

Public Properties

	Property		Defined By
		bytesAvailable : uint [read-only] The number of bytes of data available for reading from the current position in the byte array to the end of the array.	ByteArray
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		defaultObjectEncoding : uint [static] Denotes the default object encoding for the ByteArray class to use for a new ByteArray instance.	ByteArray
		endian : String Changes or reads the byte order for the data; either Endian.BIG_ENDIAN or Endian.LITTLE_ENDIAN.	ByteArray
		length : uint The length of the ByteArray object, in bytes.	ByteArray
		objectEncoding : uint Used to determine whether the ActionScript 3.0, ActionScript 2.0, or ActionScript 1.0 format should be used when writing to, or reading from, a ByteArray instance.	ByteArray
		position : uint Moves, or returns the current position, in bytes, of the file pointer into the ByteArray object.	ByteArray
		shareable : Boolean Specifies whether the underlying memory of the byte array is shareable.	ByteArray

Public Methods

	Method		Defined By
		ByteArray() Creates a ByteArray instance representing a packed array of bytes, so that you can use the methods and properties in this class to optimize your data storage and stream.	ByteArray
		atomicCompareAndSwapIntAt(byteIndex:int, expectedValue:int, newValue:int):int In a single atomic operation, compares an integer value in this byte array with another integer value and, if they match, swaps those bytes with another value.	ByteArray
		atomicCompareAndSwapLength(expectedLength:int, newLength:int):int In a single atomic operation, compares this byte array's length with a provided value and, if they match, changes the length of this byte array.	ByteArray
		clear():void Clears the contents of the byte array and resets the length and position properties to 0.	ByteArray
		compress(algorithm:String):void Compresses the byte array.	ByteArray
		deflate():void Compresses the byte array using the deflate compression algorithm.	ByteArray
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		inflate():void Decompresses the byte array using the deflate compression algorithm.	ByteArray
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		readBoolean():Boolean Reads a Boolean value from the byte stream.	ByteArray
		readByte():int Reads a signed byte from the byte stream.	ByteArray
		readBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void Reads the number of data bytes, specified by the length parameter, from the byte stream.	ByteArray
		readDouble():Number Reads an IEEE 754 double-precision (64-bit) floating-point number from the byte stream.	ByteArray
		readFloat():Number Reads an IEEE 754 single-precision (32-bit) floating-point number from the byte stream.	ByteArray
		readInt():int Reads a signed 32-bit integer from the byte stream.	ByteArray
		readMultiByte(length:uint, charSet:String):String Reads a multibyte string of specified length from the byte stream using the specified character set.	ByteArray
		readObject():* Reads an object from the byte array, encoded in AMF serialized format.	ByteArray
		readShort():int Reads a signed 16-bit integer from the byte stream.	ByteArray
		readUnsignedByte():uint Reads an unsigned byte from the byte stream.	ByteArray
		readUnsignedInt():uint Reads an unsigned 32-bit integer from the byte stream.	ByteArray
		readUnsignedShort():uint Reads an unsigned 16-bit integer from the byte stream.	ByteArray
		readUTF():String Reads a UTF-8 string from the byte stream.	ByteArray
		readUTFBytes(length:uint):String Reads a sequence of UTF-8 bytes specified by the length parameter from the byte stream and returns a string.	ByteArray
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toJSON(k:String):* Provides an overridable method for customizing the JSON encoding of values in an ByteArray object.	ByteArray
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Converts the byte array to a string.	ByteArray
		uncompress(algorithm:String):void Decompresses the byte array.	ByteArray
		valueOf():Object Returns the primitive value of the specified object.	Object
		writeBoolean(value:Boolean):void Writes a Boolean value.	ByteArray
		writeByte(value:int):void Writes a byte to the byte stream.	ByteArray
		writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void Writes a sequence of length bytes from the specified byte array, bytes, starting offset(zero-based index) bytes into the byte stream.	ByteArray
		writeDouble(value:Number):void Writes an IEEE 754 double-precision (64-bit) floating-point number to the byte stream.	ByteArray
		writeFloat(value:Number):void Writes an IEEE 754 single-precision (32-bit) floating-point number to the byte stream.	ByteArray
		writeInt(value:int):void Writes a 32-bit signed integer to the byte stream.	ByteArray
		writeMultiByte(value:String, charSet:String):void Writes a multibyte string to the byte stream using the specified character set.	ByteArray
		writeObject(object:*):void Writes an object into the byte array in AMF serialized format.	ByteArray
		writeShort(value:int):void Writes a 16-bit integer to the byte stream.	ByteArray
		writeUnsignedInt(value:uint):void Writes a 32-bit unsigned integer to the byte stream.	ByteArray
		writeUTF(value:String):void Writes a UTF-8 string to the byte stream.	ByteArray
		writeUTFBytes(value:String):void Writes a UTF-8 string to the byte stream.	ByteArray

Property Detail

bytesAvailable

property

bytesAvailable:uint [read-only]

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

The number of bytes of data available for reading from the current position in the byte array to the end of the array.

Use the bytesAvailable property in conjunction with the read methods each time you access a ByteArray object to ensure that you are reading valid data.

Implementation
public function get bytesAvailable():uint

defaultObjectEncoding

property

defaultObjectEncoding:uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Denotes the default object encoding for the ByteArray class to use for a new ByteArray instance. When you create a new ByteArray instance, the encoding on that instance starts with the value of defaultObjectEncoding. The defaultObjectEncoding property is initialized to ObjectEncoding.AMF3.

When an object is written to or read from binary data, the objectEncoding value is used to determine whether the ActionScript 3.0, ActionScript2.0, or ActionScript 1.0 format should be used. The value is a constant from the ObjectEncoding class.

Implementation
public static function get defaultObjectEncoding():uint
public static function set defaultObjectEncoding(value:uint):void

Related API Elements

ObjectEncoding class
flash.utils.ByteArray.objectEncoding

endian

property

endian:String

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Changes or reads the byte order for the data; either Endian.BIG_ENDIAN or Endian.LITTLE_ENDIAN.

Implementation
public function get endian():String
public function set endian(value:String):void

Related API Elements

Endian class

length

property

length:uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

The length of the ByteArray object, in bytes.

If the length is set to a value that is larger than the current length, the right side of the byte array is filled with zeros.

If the length is set to a value that is smaller than the current length, the byte array is truncated.

Implementation
public function get length():uint
public function set length(value:uint):void

objectEncoding

property

objectEncoding:uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Used to determine whether the ActionScript 3.0, ActionScript 2.0, or ActionScript 1.0 format should be used when writing to, or reading from, a ByteArray instance. The value is a constant from the ObjectEncoding class.

Implementation
public function get objectEncoding():uint
public function set objectEncoding(value:uint):void

Related API Elements

ObjectEncoding class
flash.utils.ByteArray.defaultObjectEncoding

position

property

position:uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Moves, or returns the current position, in bytes, of the file pointer into the ByteArray object. This is the point at which the next call to a read method starts reading or a write method starts writing.

Implementation
public function get position():uint
public function set position(value:uint):void

shareable

property

shareable:Boolean

Language Version:

ActionScript 3.0

Runtime Versions:

Flash Player 11.5, AIR 3.5

Specifies whether the underlying memory of the byte array is shareable. For a shareable byte array, all ByteArray instances in all workers that reference the byte array use the same underlying system memory. The default value is false, indicating that the underlying memory is not shared among workers.

This property also affects what the runtime does with this byte array if it is passed to a worker using the Worker.setSharedProperty() method or the MessageChannel.send() method:

Not shareable: If this property is false, when the byte array is passed to a worker the runtime creates a complete copy of the byte array, including allocating a new segment of memory in which to store the duplicate byte array's contents
Shareable: If this property is true, when the byte array is passed to a worker the runtime uses the same underlying memory as the storage buffer for the contents of both the original ByteArray instance and the new ByteArray instance created for the second worker. In essence, both ByteArray instances contain a reference to the same underlying byte array.

The ability to access a shared byte array from multiple workers simultaneously can result in an undesirable situation where both workers are manipulating the byte array's underlying memory at the same time. You can use several mechanisms to control access to shared memory:

the compare-and-swap mechanisms provided by the ByteArray class's atomicCompareAndSwapIntAt() and atomicCompareAndSwapLength() methods
the specialized mechanisms provided by the Mutex and Condition classes (in the flash.concurrent package)

Setting this property to true only affects subsequent code that passes this byte array to a worker. Any copy of this byte array that has already been passed to a worker continues to exist as a separate copy.

If you set this property to false when it is previously true, the underlying memory for the byte array is immediately copied into a new segment of system memory. This ByteArray instance then uses the new underlying memory from that point on. Consequently, this byte array's underlying memory is no longer shared with other workers even if it was previously shared. If you subsequently pass this byte array to a worker, its underlying memory is copied as with any ByteArray object whose shareable property is false.

The default value is false.

Implementation
public function get shareable():Boolean
public function set shareable(value:Boolean):void

Related API Elements

Worker class
Worker.setSharedProperty() method
MessageChannel.send() method
atomicCompareAndSwapIntAt() method
atomicCompareAndSwapLength() method
Mutex class
Condition class

Constructor Detail

ByteArray

()

Constructor

public function ByteArray()

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Creates a ByteArray instance representing a packed array of bytes, so that you can use the methods and properties in this class to optimize your data storage and stream.

Method Detail

atomicCompareAndSwapIntAt

()

method

public function atomicCompareAndSwapIntAt(byteIndex:int, expectedValue:int, newValue:int):int

Language Version:

ActionScript 3.0

Runtime Versions:

Flash Player 11.5, AIR 3.5

In a single atomic operation, compares an integer value in this byte array with another integer value and, if they match, swaps those bytes with another value.

This method is intended to be used with a byte array whose underlying memory is shared between multiple workers (the ByteArray instance's shareable property is true). It performs the following sequence of steps:

Reads an integer value from this byte array starting at the index (measured in bytes) specified in the byteIndex argument
Compares the actual value from this byte array to the value passed in the expectedValue argument
If the two values are equal, it writes the value in the newValue argument into the byte array at the location specified by the byteIndex parameter and returns the value that was previously contained in those bytes (the value read in step 1)
Otherwise, the contents of the byte array are not changed and the method returns the actual value read from the byte array

All these steps are performed in one atomic hardware transaction. This guarantees that no operations from other workers make changes to the contents of the byte array during the compare-and-swap operation.

Parameters

	`byteIndex:int` — the index position (in bytes) from which the integer to compare is read, and to which the `newValue` value is written if the comparison results in a match. This value must be a multiple of 4.

	`expectedValue:int` — the value that is expected to match the contents of the byte array at the specified index

	`newValue:int` — the new value that replaces the contents of the byte array at the specified index if the comparison results in a match

Returns

int — the previous value at the specified location if the comparison results in a match, or the actual value from the byte array if the actual value and expected value don't match

Throws

ArgumentError — if the byteIndex value is not a multiple of 4 or if it's negative

Related API Elements

ByteArray.shareable property
Worker class

atomicCompareAndSwapLength

()

method

public function atomicCompareAndSwapLength(expectedLength:int, newLength:int):int

Language Version:

ActionScript 3.0

Runtime Versions:

Flash Player 11.5, AIR 3.5

In a single atomic operation, compares this byte array's length with a provided value and, if they match, changes the length of this byte array.

This method is intended to be used with a byte array whose underlying memory is shared between multiple workers (the ByteArray instance's shareable property is true). It does the following:

Reads the integer length property of the ByteArray instance
Compares the length to the value passed in the expectedLength argument
If the two values are equal, it changes the byte array's length to the value passed as the newLength parameter, either growing or shrinking the size of the byte array
Otherwise, the byte array is not changed

Parameters

	`expectedLength:int` — the expected value of the ByteArray's `length` property. If the specified value and the actual value match, the byte array's length is changed.

	`newLength:int` — the new length value for the byte array if the comparison succeeds

Returns

int — the previous length value of the ByteArray, regardless of whether or not it changed

Related API Elements

ByteArray.shareable property
Worker class

clear

()

method

public function clear():void

Language Version:

ActionScript 3.0

Runtime Versions:

Flash Player 10, AIR 1.5, Flash Lite 4

Clears the contents of the byte array and resets the length and position properties to 0. Calling this method explicitly frees up the memory used by the ByteArray instance.

compress

()

method

public function compress(algorithm:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9

Compresses the byte array. The entire byte array is compressed. After the call, the length property of the ByteArray is set to the new length. The position property is set to the end of the byte array.

You specify a compression algorithm by passing a value (defined in the CompressionAlgorithm class) as the algorithm parameter. The supported algorithms include the following:

The zlib compressed data format is described at http://www.ietf.org/rfc/rfc1950.txt.

The deflate compression algorithm is described at http://www.ietf.org/rfc/rfc1951.txt.

The lzma compression algorithm is described at http://www.7-zip.org/7z.html.

The deflate compression algorithm is used in several compression formats, such as zlib, gzip, some zip implementations, and others. When data is compressed using one of those compression formats, in addition to storing the compressed version of the original data, the compression format data (for example, the .zip file) includes metadata information. Some examples of the types of metadata included in various file formats are file name, file modification date/time, original file size, optional comments, checksum data, and more.

For example, when a ByteArray is compressed using the zlib algorithm, the resulting ByteArray is structured in a specific format. Certain bytes contain metadata about the compressed data, while other bytes contain the actual compressed version of the original ByteArray data. As defined by the zlib compressed data format specification, those bytes (that is, the portion containing the compressed version of the original data) are compressed using the deflate algorithm. Consequently those bytes are identical to the result of calling compress(air.CompressionAlgorithm.DEFLATE) on the original ByteArray. However, the result from compress(air.CompressionAlgorithm.ZLIB) includes the extra metadata, while the compress(CompressionAlgorithm.DEFLATE) result includes only the compressed version of the original ByteArray data and nothing else.

In order to use the deflate format to compress a ByteArray instance's data in a specific format such as gzip or zip, you cannot simply call compress(CompressionAlgorithm.DEFLATE). You must create a ByteArray structured according to the compression format's specification, including the appropriate metadata as well as the compressed data obtained using the deflate format. Likewise, in order to decode data compressed in a format such as gzip or zip, you can't simply call uncompress(CompressionAlgorithm.DEFLATE) on that data. First, you must separate the metadata from the compressed data, and you can then use the deflate format to decompress the compressed data.

Parameters

algorithm:String (default = NaN) — The compression algorithm to use when compressing. Valid values are defined as constants in the CompressionAlgorithm class. The default is to use zlib format. Calling compress(CompressionAlgorithm.DEFLATE) has the same effect as calling the deflate() method. Support for the lzma algorithm was added for Flash Player 11.3 and AIR 3.3. You must have those player versions, or later, to use lzma compression.

Related API Elements

uncompress()
flash.utils.CompressionAlgorithm

deflate

()

method

public function deflate():void

Language Version:

ActionScript 3.0

Runtime Versions:

Flash Player 10, AIR 1.5, Flash Lite 4

Compresses the byte array using the deflate compression algorithm. The entire byte array is compressed.

After the call, the length property of the ByteArray is set to the new length. The position property is set to the end of the byte array.

The deflate compression algorithm is described at http://www.ietf.org/rfc/rfc1951.txt.

In order to use the deflate format to compress a ByteArray instance's data in a specific format such as gzip or zip, you cannot simply call deflate(). You must create a ByteArray structured according to the compression format's specification, including the appropriate metadata as well as the compressed data obtained using the deflate format. Likewise, in order to decode data compressed in a format such as gzip or zip, you can't simply call inflate() on that data. First, you must separate the metadata from the compressed data, and you can then use the deflate format to decompress the compressed data.

Related API Elements

inflate()

inflate

()

method

public function inflate():void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 10

Decompresses the byte array using the deflate compression algorithm. The byte array must have been compressed using the same algorithm.

After the call, the length property of the ByteArray is set to the new length. The position property is set to 0.

The deflate compression algorithm is described at http://www.ietf.org/rfc/rfc1951.txt.

In order to decode data compressed in a format that uses the deflate compression algorithm, such as data in gzip or zip format, it will not work to simply call inflate() on a ByteArray containing the compression formation data. First, you must separate the metadata that is included as part of the compressed data format from the actual compressed data. For more information, see the compress() method description.

Throws

IOError — The data is not valid compressed data; it was not compressed with the same compression algorithm used to compress.

Related API Elements

deflate()

readBoolean

()

method

public function readBoolean():Boolean

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a Boolean value from the byte stream. A single byte is read, and true is returned if the byte is nonzero, false otherwise.

Returns

Boolean — Returns true if the byte is nonzero, false otherwise.

Throws

EOFError — There is not sufficient data available to read.

readByte

()

method

public function readByte():int

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a signed byte from the byte stream.

The returned value is in the range -128 to 127.

Returns

int — An integer between -128 and 127.

Throws

EOFError — There is not sufficient data available to read.

readBytes

()

method

public function readBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads the number of data bytes, specified by the length parameter, from the byte stream. The bytes are read into the ByteArray object specified by the bytes parameter, and the bytes are written into the destination ByteArray starting at the position specified by offset.

Parameters

	`bytes:ByteArray` — The ByteArray object to read data into.

	`offset:uint` (default = `0`) — The offset (position) in `bytes` at which the read data should be written.

	`length:uint` (default = `0`) — The number of bytes to read. The default value of 0 causes all available data to be read.

Throws

	`EOFError` — There is not sufficient data available to read.

	`RangeError` — The value of the supplied offset and length, combined, is greater than the maximum for a uint.

More examples

Reading and writing a ByteArray

readDouble

()

method

public function readDouble():Number

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads an IEEE 754 double-precision (64-bit) floating-point number from the byte stream.

Returns

Number — A double-precision (64-bit) floating-point number.

Throws

EOFError — There is not sufficient data available to read.

readFloat

()

method

public function readFloat():Number

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads an IEEE 754 single-precision (32-bit) floating-point number from the byte stream.

Returns

Number — A single-precision (32-bit) floating-point number.

Throws

EOFError — There is not sufficient data available to read.

readInt

()

method

public function readInt():int

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a signed 32-bit integer from the byte stream.

The returned value is in the range -2147483648 to 2147483647.

Returns

int — A 32-bit signed integer between -2147483648 and 2147483647.

Throws

EOFError — There is not sufficient data available to read.

readMultiByte

()

method

public function readMultiByte(length:uint, charSet:String):String

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a multibyte string of specified length from the byte stream using the specified character set.

Parameters

	`length:uint` — The number of bytes from the byte stream to read.

	`charSet:String` — The string denoting the character set to use to interpret the bytes. Possible character set strings include `"shift-jis"`, `"cn-gb"`, `"iso-8859-1"`, and others. For a complete list, see Supported Character Sets. Note: If the value for the `charSet` parameter is not recognized by the current system, the application uses the system's default code page as the character set. For example, a value for the `charSet` parameter, as in `myTest.readMultiByte(22, "iso-8859-01")` that uses `01` instead of `1` might work on your development system, but not on another system. On the other system, the application will use the system's default code page.

Returns

String — UTF-8 encoded string.

Throws

EOFError — There is not sufficient data available to read.

readObject

()

method

public function readObject():*

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads an object from the byte array, encoded in AMF serialized format.

Returns

* — The deserialized object.

Throws

EOFError — There is not sufficient data available to read.

Related API Elements

flash.net.registerClassAlias()

readShort

()

method

public function readShort():int

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a signed 16-bit integer from the byte stream.

The returned value is in the range -32768 to 32767.

Returns

int — A 16-bit signed integer between -32768 and 32767.

Throws

EOFError — There is not sufficient data available to read.

readUnsignedByte

()

method

public function readUnsignedByte():uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads an unsigned byte from the byte stream.

The returned value is in the range 0 to 255.

Returns

uint — A 32-bit unsigned integer between 0 and 255.

Throws

EOFError — There is not sufficient data available to read.

readUnsignedInt

()

method

public function readUnsignedInt():uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads an unsigned 32-bit integer from the byte stream.

The returned value is in the range 0 to 4294967295.

Returns

uint — A 32-bit unsigned integer between 0 and 4294967295.

Throws

EOFError — There is not sufficient data available to read.

readUnsignedShort

()

method

public function readUnsignedShort():uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads an unsigned 16-bit integer from the byte stream.

The returned value is in the range 0 to 65535.

Returns

uint — A 16-bit unsigned integer between 0 and 65535.

Throws

EOFError — There is not sufficient data available to read.

readUTF

()

method

public function readUTF():String

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a UTF-8 string from the byte stream. The string is assumed to be prefixed with an unsigned short indicating the length in bytes.

Returns

String — UTF-8 encoded string.

Throws

EOFError — There is not sufficient data available to read.

Related API Elements

flash.utils.IDataInput.readUTF()

readUTFBytes

()

method

public function readUTFBytes(length:uint):String

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Reads a sequence of UTF-8 bytes specified by the length parameter from the byte stream and returns a string.

Parameters

length:uint — An unsigned short indicating the length of the UTF-8 bytes.

Returns

String — A string composed of the UTF-8 bytes of the specified length.

Throws

EOFError — There is not sufficient data available to read.

toJSON

()

method

public function toJSON(k:String):*

Language Version:

ActionScript 3.0

Runtime Versions:

Flash Player 11, AIR 3, Flash Lite 4

Provides an overridable method for customizing the JSON encoding of values in an ByteArray object.

The JSON.stringify() method looks for a toJSON() method on each object that it traverses. If the toJSON() method is found, JSON.stringify() calls it for each value it encounters, passing in the key that is paired with the value.

ByteArray provides a default implementation of toJSON() that simply returns the name of the class. Because the content of any ByteArray requires interpretation, clients that wish to export ByteArray objects to JSON must provide their own implementation. You can do so by redefining the toJSON() method on the class prototype.

The toJSON() method can return a value of any type. If it returns an object, stringify() recurses into that object. If toJSON() returns a string, stringify() does not recurse and continues its traversal.

Parameters

k:String — The key of a key/value pair that JSON.stringify() has encountered in its traversal of this object

Returns

* — The class name string.

Learn more

Overview of the JSON API

Related API Elements

Object
Object.prototype

toString

()

method

public function toString():String

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Converts the byte array to a string. If the data in the array begins with a Unicode byte order mark, the application will honor that mark when converting to a string. If System.useCodePage is set to true, the application will treat the data in the array as being in the current system code page when converting.

Returns

String — The string representation of the byte array.

uncompress

()

method

public function uncompress(algorithm:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Decompresses the byte array. After the call, the length property of the ByteArray is set to the new length. The position property is set to 0.

The byte array must have been compressed using the same algorithm as the uncompress. You specify an uncompression algorithm by passing a value (defined in the CompressionAlgorithm class) as the algorithm parameter. The supported algorithms include the following:

The zlib compressed data format is described at http://www.ietf.org/rfc/rfc1950.txt.

The deflate compression algorithm is described at http://www.ietf.org/rfc/rfc1951.txt.

The lzma compression algorithm is described at http://www.7-zip.org/7z.html.

In order to decode data compressed in a format that uses the deflate compression algorithm, such as data in gzip or zip format, it will not work to call uncompress(CompressionAlgorithm.DEFLATE) on a ByteArray containing the compression formation data. First, you must separate the metadata that is included as part of the compressed data format from the actual compressed data. For more information, see the compress() method description.

Parameters

algorithm:String (default = NaN) — The compression algorithm to use when decompressing. This must be the same compression algorithm used to compress the data. Valid values are defined as constants in the CompressionAlgorithm class. The default is to use zlib format. Support for the lzma algorithm was added for Flash Player 11.3 and AIR 3.3. You must have those player versions, or later, to use lzma.

Throws

IOError — The data is not valid compressed data; it was not compressed with the same compression algorithm used to compress.

Related API Elements

compress()
flash.utils.CompressionAlgorithm

writeBoolean

()

method

public function writeBoolean(value:Boolean):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a Boolean value. A single byte is written according to the value parameter, either 1 if true or 0 if false.

Parameters

value:Boolean — A Boolean value determining which byte is written. If the parameter is true, the method writes a 1; if false, the method writes a 0.

writeByte

()

method

public function writeByte(value:int):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a byte to the byte stream.

The low 8 bits of the parameter are used. The high 24 bits are ignored.

Parameters

value:int — A 32-bit integer. The low 8 bits are written to the byte stream.

writeBytes

()

method

public function writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a sequence of length bytes from the specified byte array, bytes, starting offset(zero-based index) bytes into the byte stream.

If the length parameter is omitted, the default length of 0 is used; the method writes the entire buffer starting at offset. If the offset parameter is also omitted, the entire buffer is written.

If offset or length is out of range, they are clamped to the beginning and end of the bytes array.

Parameters

	`bytes:ByteArray` — The ByteArray object.

	`offset:uint` (default = `0`) — A zero-based index indicating the position into the array to begin writing.

	`length:uint` (default = `0`) — An unsigned integer indicating how far into the buffer to write.

More examples

Reading and writing a ByteArray

writeDouble

()

method

public function writeDouble(value:Number):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes an IEEE 754 double-precision (64-bit) floating-point number to the byte stream.

Parameters

value:Number — A double-precision (64-bit) floating-point number.

writeFloat

()

method

public function writeFloat(value:Number):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes an IEEE 754 single-precision (32-bit) floating-point number to the byte stream.

Parameters

value:Number — A single-precision (32-bit) floating-point number.

writeInt

()

method

public function writeInt(value:int):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a 32-bit signed integer to the byte stream.

Parameters

value:int — An integer to write to the byte stream.

writeMultiByte

()

method

public function writeMultiByte(value:String, charSet:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a multibyte string to the byte stream using the specified character set.

Parameters

	`value:String` — The string value to be written.

	`charSet:String` — The string denoting the character set to use. Possible character set strings include `"shift-jis"`, `"cn-gb"`, `"iso-8859-1"`, and others. For a complete list, see Supported Character Sets.

writeObject

()

method

public function writeObject(object:*):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes an object into the byte array in AMF serialized format.

Parameters

object:* — The object to serialize.

Related API Elements

flash.net.registerClassAlias()

writeShort

()

method

public function writeShort(value:int):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a 16-bit integer to the byte stream. The low 16 bits of the parameter are used. The high 16 bits are ignored.

Parameters

value:int — 32-bit integer, whose low 16 bits are written to the byte stream.

writeUnsignedInt

()

method

public function writeUnsignedInt(value:uint):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a 32-bit unsigned integer to the byte stream.

Parameters

value:uint — An unsigned integer to write to the byte stream.

writeUTF

()

method

public function writeUTF(value:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a UTF-8 string to the byte stream. The length of the UTF-8 string in bytes is written first, as a 16-bit integer, followed by the bytes representing the characters of the string.

Parameters

value:String — The string value to be written.

Throws

RangeError — If the length is larger than 65535.

writeUTFBytes

()

method

public function writeUTFBytes(value:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0, Flash Player 9, Flash Lite 4

Writes a UTF-8 string to the byte stream. Similar to the writeUTF() method, but writeUTFBytes() does not prefix the string with a 16-bit length word.

Parameters

value:String — The string value to be written.

Examples How to use this example

ByteArrayExample.as

The following example uses the class ByteArrayExample to write a Boolean and the double-precision floating-point representation of pi to a byte array. This is accomplished using the following steps:

Declare a new ByteArray object instance byteArr.
Write the byte-equivalent value of the Boolean false and then check the length and read it back.
Write the double-precision floating-point equivalent of the mathematical value of pi.
Read back each of the nine bytes written into the byte array.

Note: when trace() is called on a byte, it prints the decimal equivalent of the bytes stored in the byte array.

Notice how a code segment is added at the end to check for end of file errors to ensure that the byte stream is not read past its end.

package {
    import flash.display.Sprite;
    import flash.utils.ByteArray;
    import flash.errors.EOFError;

    public class ByteArrayExample extends Sprite {        
        public function ByteArrayExample() {
            var byteArr:ByteArray = new ByteArray();

            byteArr.writeBoolean(false);
            trace(byteArr.length);            // 1
            trace(byteArr[0]);            // 0

            byteArr.writeDouble(Math.PI);
            trace(byteArr.length);            // 9
            trace(byteArr[0]);            // 0
            trace(byteArr[1]);            // 64
            trace(byteArr[2]);            // 9
            trace(byteArr[3]);            // 33
            trace(byteArr[4]);            // 251
            trace(byteArr[5]);            // 84
            trace(byteArr[6]);            // 68
            trace(byteArr[7]);            // 45
            trace(byteArr[8]);            // 24
            
            byteArr.position = 0;

            try {
                trace(byteArr.readBoolean() == false); // true
            } 
            catch(e:EOFError) {
                trace(e);           // EOFError: Error #2030: End of file was encountered.
            }
            
            try {
                trace(byteArr.readDouble());        // 3.141592653589793
            }
            catch(e:EOFError) {
                trace(e);           // EOFError: Error #2030: End of file was encountered.
            }
            
            try {
                trace(byteArr.readDouble());
            } 
            catch(e:EOFError) {
                trace(e);            // EOFError: Error #2030: End of file was encountered.
            }
        }
    }
}

Legal Notices | Online Privacy Policy

ByteArray - AS3

Classes x

bytesAvailable

defaultObjectEncoding

endian

length

objectEncoding

position

shareable

ByteArray

atomicCompareAndSwapIntAt

atomicCompareAndSwapLength

clear

compress

deflate

inflate

readBoolean

readByte

readBytes

readDouble

readFloat

readInt

readMultiByte

readObject

readShort

readUnsignedByte

readUnsignedInt

readUnsignedShort

readUTF

readUTFBytes

toJSON

toString

uncompress

writeBoolean

writeByte

writeBytes

writeDouble

writeFloat

writeInt

writeMultiByte

writeObject

writeShort

writeUnsignedInt

writeUTF

writeUTFBytes