Async or sync resolution?

obs-vs-promises-resolution.js

console.log(1);

new Promise(function(resolve,reject){
    console.log(2);
    resolve();
}).then(function(val){
    console.log(3);
});


const Rx = require('rxjs');

let obs = Rx.Observable.create(sub => {

    console.log(4);
    sub.next();

});


obs = obs.map(v => {
    console.log(5);
    return 'foo';
});


obs.subscribe(v => {
    console.log(6);
    // 'foo'
});

console.log(7);