Rx.Observable.prototype.includes(searchElement, [fromIndex])

Determines whether an observable sequence includes a specified element with an optional from index.

参数

1. searchElement (Any): The value to locate in the source sequence.
2. [fromIndex] (Number): The index to start the search. If not specified, defaults to 0.

返回值

(Observable): An observable sequence containing a single element determining whether the source sequence includes an element that has the specified value with an optional from index.

例

/* Without an index */
var source = Rx.Observable.of(42)
  .includes(42);

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
      console.log('Completed');
  });

// => Next: true
// => Completed

/* With an index */
var source = Rx.Observable.of(1,2,3)
  .includes(2, 1);

var subscription = source.subscribe(
  function (x) {
    console.log('Next: %s', x);
  },
  function (err) {
    console.log('Error: %s', err);
  },
  function () {
    console.log('Completed');
  });

// => Next: true
// => Completed