The ElementAt operator pulls an item located at a specified index location in the sequence
of items emitted by the source Observable and emits that item as its own sole emission.
TBD
TBD
RxGroovy implements this operator as elementAt. Pass elementAt a zero-based
index value and it will emit the solitary item from the source Observable’s sequence that matches
that index value (for example, if you pass the index value 5, elementAt will emit the sixth
item emitted by the source Observable).
If you pass in a negative index value, or if the source Observable emits fewer than index
value + 1 items, elementAt will throw an
IndexOutOfBoundsException.
ReactiveXelementAt(int)
RxGroovy also implements the elementAtOrDefault operator. It differs from
elementAt in that it will not throw an exception if the source Observable emits fewer than
index value + 1 items. Instead, it will emit a “default” item
that you specify with an additional parameter to elementAtOrDefault.
If you pass in a negative index value, elementAt will throw an
IndexOutOfBoundsException.
elementAtOrDefault(int,T)
elementAt and elementAtOrDefault do not by default operate on any particular
Scheduler.
RxGroovy implements this operator as elementAt. Pass elementAt a zero-based
index value and it will emit the solitary item from the source Observable’s sequence that matches
that index value (for example, if you pass the index value 5, elementAt will emit the sixth
item emitted by the source Observable).
If you pass in a negative index value, or if the source Observable emits fewer than index
value + 1 items, elementAt will throw an
IndexOutOfBoundsException.
elementAt(int)
RxGroovy also implements the elementAtOrDefault operator. It differs from
elementAt in that it will not throw an exception if the source Observable emits fewer than
index value + 1 items. Instead, it will emit a “default” item
that you specify with an additional parameter to elementAtOrDefault.
If you pass in a negative index value, elementAt will throw an
IndexOutOfBoundsException.
elementAtOrDefault(int,T)
elementAt and elementAtOrDefault do not by default operate on any particular
Scheduler.
RxJS implements this operator as elementAt. Pass elementAt a zero-based
index value and it will emit the solitary item from the source Observable’s sequence that matches
that index value (for example, if you pass the index value 5, elementAt will emit the sixth
item emitted by the source Observable).
If there is no element in the source sequence with the index value you specify, elementAt
will issue an onError notification: “Argument out of range”
var source = Rx.Observable.fromArray([1,2,3,4])
.elementAt(1);
var subscription = source.subscribe(
function (x) { console.log('Next: ' + x); },
function (err) { console.log('Error: ' + err); },
function () { console.log('Completed'); });Next: 2 Completed
You may optionally pass in a default value that elementAt will emit if the
source Observable emits no values:
var source = Rx.Observable.fromArray([])
.element({defaultValue: 23});
var subscription = source.subscribe(
function (x) { console.log('Next: ' + x); },
function (err) { console.log('Error: ' + err); },
function () { console.log('Completed'); });Next: 23 Completed
elementAt is found in each of the following distributions:
rx.all.jsrx.all.compat.jsrx.aggregates.jsThey require one of the following distributions:
rx.jsrx.compat.jsrx.lite.jsrx.lite.compat.js