There are more operators in the filtering category besides filter(). This lesson will teach how take(), first(), and skip() are simply operators to ignore or pass a certain amount of events from the source Observable.
take(number):
var foo = Rx.Observable.interval(100); /*
--0--1--2--3--4--5--6--7-
take(5)
--0--1--2--3--4
*/ var bar = foo.take(5); bar.subscribe(
function (x) { console.log('next ' + x); },
function (err) { console.log('error ' + err); },
function () { console.log('done'); },
); /**
"next 0"
"next 1"
"next 2"
"next 3"
"next 4"
"done"
*/
first():
var foo = Rx.Observable.interval(100); /*
--0--1--2--3--4--5--6--7-
first()
--0
*/ var bar = foo.first(); bar.subscribe(
function (x) { console.log('next ' + x); },
function (err) { console.log('error ' + err); },
function () { console.log('done'); },
); /**
"next 0"
"done"
*/
skip(number): different with take(), it skip the first number of item, and show the rest:
var foo = Rx.Observable.interval(100); /*
--0--1--2--3--4--5--6--7
skip(5).take(3)
-----------------5--6--7
*/ var bar = foo.skip(5).take(3); bar.subscribe(
function (x) { console.log('next ' + x); },
function (err) { console.log('error ' + err); },
function () { console.log('done'); },
); /**
"next 5"
"next 6"
"next 7"
"done"
*/