readonly unsigned long length
The number of StyleSheet objects in the array.
item( )
Returns the StyleSheet object at the specified position in the array, or null if the specified position is negative or is greater than or equal to length.
This interface defines an array of StyleSheet objects. length specifies the number of style sheets in the array, and item( ) provides a way to retrieve the style sheet at a given position. In JavaScript, you can treat a StyleSheetList object as a read-only array, and you can index it using ordinary square-bracket array notation instead of calling the item( ) method.
DocumentStyle.styleSheets