rxjs operator

rxjsOperator.js

function log() {
  return Rx.Observable.create((observer) => {
    return this.subscribe(
      (value) => {
        console.log(value);
        try {
          observer.next(value);
        } catch (e) {
          observer.error(e);
        }
      },
      (err) => {
        console.log(err);
        observer.error(err);
      },
      () => {
        observer.complete();
      }
    );
  });
}