map | select

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.

Arguments

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.

Returns

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

Example