Rx.Observable.prototype.map(selector, [thisArg])

Projects each element of an observable sequence into a new form by incorporating the element's index. This is an alias for the select method.

参数

1. selector (Function): Transform function to apply to each source element. The selector is called with the following information:
   1. the value of the element
   2. the index of the element
   3. the Observable object being subscribed
2. [thisArg] (Any): Object to use as this when executing the predicate.

返回值

(Observable): An observable sequence which results from the comonadic bind operation.

例