how to make a rxjs observable a method code example

Example 1: understanding Observable.create(

import { Observable } from "rxjs/Observable";

var observable = Observable.create(function subscribe(observer) {
    observer.next('Hey guys!')
})

// OR 

var observable = Observable.create((observer:any) => {
    observer.next('Hey guys!')
})

Example 2: rxjs create observable from value

// Requires RXJS 6+
// Create an observable of any Type
// Ask yourself if the function creates a new observable or not
// If it creates a new one then it is imported from 'rxjs'
// Operators are imported from 'rxjs/operators'
import { of } from 'rxjs';

// T => Observable<T>
const value$ = of(1);