Rx.Observable.prototype.indexOf(searchElement, fromIndex)
Returns the first index at which a given element can be found in the observable sequence, or -1 if it is not present.
参数
searchElement
(Any
): An element to locate in the array.fromIndex
(Number): The index to start the search. If not specified, defaults to 0.
返回值
(Observable
): An observable sequence containing the first index at which a given element can be found in the observable sequence, or -1 if it is not present.