as3数据类型说明（AS3 data type description）.doc

as3数据类型说明（AS3 data type description） AS3 data type description The base metadata types include Boolean, int, Null, Number, String, uint, and void. The ActionScript core class also defines the following complex data types: Object, Array, Date, Error, Function, RegExp, XML, and XMLList. Boolean data type The Boolean data type contains two values: true and false. For variables of type Boolean, any other values are invalid. The default value of a boolean variable that has been declared but uninitialized is false. Int data type The int data type is internally stored as a 32 bit integer containing a set of integers between -2147483648 (-231) and 2147483647 (231 - 1) (including -2147483648 and 2147483647). The earlier version of ActionScript provided only the Number data type, which can be used both for integers and floating points. In ActionScript 3, you can now access 32 bit machine types with signed integers and unsigned integers. If your variable will not use floating-point numbers, then using the int data type instead of the Number data type should be faster and more efficient. The Number data type should be used for integer values less than int or greater than the maximum value of int. The Number data type can handle values between -9007199254740992 and 9007199254740992 (53 bit integer values). The default value of a variable for the int data type is 0. Null data type The Null data type contains only one value: null. This is the default value for the String data type and all classes (including the Object class) used to define complex data types. Other base metadata types, such as Boolean, Number, int, and uint, do not contain null values. If you try to assign null to variables such as Boolean, Number, int, or uint, Flash Player converts the null value to the corresponding default value. The Null data type cannot be used as a type annotation. Number data type In ActionScript 3, the Number data type can represent integers, unsigned integers, and floating points. Howeve