The flash.utils package contains utility classes, such as data structures like ByteArray.

 clearInterval Cancels a specified setInterval() call.
 clearTimeout Cancels a specified setTimeout() call.
 describeType Produces an XML object that describes the ActionScript object named as the parameter of the method.
 escapeMultiByte Returns an escaped copy of the input string encoded as either UTF-8 or system code page, depending on the value of System.useCodePage.
 getDefinitionByName Returns a reference to the class object of the class specified by the name parameter.
 getQualifiedClassName Returns the fully qualified class name of an object.
 getQualifiedSuperclassName Returns the fully qualified class name of the base class of the object specified by the value parameter.
 getTimer Used to compute relative time.
 setInterval Runs a function at a specified interval (in milliseconds).
 setTimeout Runs a specified function after a specified delay (in milliseconds).
 unescapeMultiByte Returns an unescaped copy of the input string, which is decoded from either system code page page or UTF-8 depending on the value of System.useCodePage.
 IDataInput The IDataInput interface provides a set of methods for reading binary data.
 IDataOutput The IDataOutput interface provides a set of methods for writing binary data.
 IExternalizable The IExternalizable interface provides control over serialization of a class as it is encoded into a data stream.
 ByteArray The ByteArray class provides methods and properties to optimize reading, writing, and working with binary data.
 CompressionAlgorithm The CompressionAlgorithm class defines string constants for the names of compress and uncompress options.
 Dictionary The Dictionary class lets you create a dynamic collection of properties, which uses strict equality (===) for key comparison.
 Endian The Endian class contains values that denote the byte order used to represent multibyte numbers.
 Proxy The Proxy class lets you override the default behavior of ActionScript operations (such as retrieving and modifying properties) on an object.
 Timer The Timer class is the interface to timers, which let you run code on a specified time sequence.