1.do
const source = Rx.Observable.of([1,2,3,4,5]);
const example = source
.do( val => console.log(`beforeMap:${val}`))
.map( val => val + 10)
.do( val => console.log(`afterMap${val}`));
const subscrbe = { }; // 11 12 13 14 15
2.toPromise
将observable转换成promise
const sample = val => Rx.Observable.of(val).delay(5000);
const example = sample('firstExample').toPromise().then(result => console.log(result))
3. reduce
将源observable的值归并为单个值，
当源observable完成时将这个值发出
累加
const source = Rx.Observable.of(1,2,3,4);
const example = source.reduce(
(acc, val) => acc + val
);
const subscribe = { }; // 10
4. scan
随着时间的推移进行归并
const subject = new Rx.Subject();
const example = subject.startWith(0).scan(
(acc, curr) => acc + curr
);
const subscrbe = { };
subject.next(1); // 1
subject.next(2); // 3
subject.next(3); // 6
5. expand
递归调用提供的函数
const source = Rx.Observable.of(2);
const example = source.expand(
val => {
console.log(`value: ${val}`);
// 2 3 4 5 6
return Rx.Observable.of(1 + val);
}
).take(5);
const subscribe = { }; // 2 3 4 5 6
5. groupBy
const people = [
{ name: 'Sue', age: 22},
{ name: 'Joe', age: 23},
{ name: 'Frank', age: 22},
{ name: 'Surah', age: 25}
];
const source = Rx.Observable.from(prople);
const example = source.groupBy(
person => person.age
).mergeMap(
group => group.toArray()
);
const subscribe = { };
// [ { name: 'Sue', age: 22},{ name: 'Frank', age: 22}]
// [{ name: 'Joe', age: 23}]
// [{ name: 'Surah', age: 25}]
6.pluck
根据属性来发出
const source = Rx.Observale.from([
{ name: 'Joe', age: 20},
{ name: 'Bob', age: 25},
]);
const example = source.pluck('name');
const subscribe = { }; // Joe Bob
const source = Rx.observable.from([
{
name: 'Joe',
age: 22,
obj: {
title: 'Developer',
language: 'Javascript'
}
},
{
name: 'Sarah',
age: 25
}
]);
const example = Rx.Observable.pluck('job', 'title');
const subscribe = { }; // Developer undefined
7.partition
分隔
// 分隔偶数奇数
const source = Rx.Observable.from([1,2,3,4,5,6]);
const [events, odds] = source.partition(val => val % 2 === 0);
const subscribe = Rx.Observable.merge(
events.map(val => `Event: ${val}`),
odds.map(val => `Odd: ${val}`)
).subscribe(
val => console.log(val)
);
9. throttle
仅当由提供的函数所确定的持续时间已经过去时才发出值
const source = Rx.Observable.interval(1000);
const example = source.throttle(val => Rx.Observable.interval(2000));
const subscrbe = { }; // 0 3 6 9
10.throttleTime
当指定的持续时间经过后发出最新值
const source = Rx.Observable.interval(1000);
const example = source.throttleTimeo(5000);
const subscribe = { }; // 0 6 12
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