The three special types are the untyped specifier (*), void, and Null.


 类型说明
 *Specifies that a property is untyped.
 voidSpecifies that a function cannot return any value.
 NullA special data type that represents the lack of a value.
特殊类型详细信息
* 特殊类型
用法
    propertyName:*

Specifies that a property is untyped. Use of the asterisk symbol for a type annotation is equivalent to using no type annotation. Expressions that read from untyped properties are considered untyped expressions. Use of untyped expressions or properties is recommended in the following circumstances:

另请参见

void 特殊类型  
用法
    functionName():void {}

Specifies that a function cannot return any value. The void type is a special type that contains exactly one value: undefined. It is special in that its use is limited to the return type of a function. You cannot use void as a type annotation for a property.

另请参见

Null 特殊类型  

A special data type that represents the lack of a value. The Null data type includes only one value: null. The Null data type is special in that it is not associated with a class. This means that you cannot use the Null data type as a type annotation for a property.

另请参见