Mongodb add an object to an object - mongodb

Question

Say I have a mongodb document I'm trying to update. The schema is level1 (object)> level2 (object) > "objects".
If I want to add another object to the end, what is the method to do that? Do I use findoneandupdate?
I'm trying to append an object to an object
As of right now, it overwrites whatever is in the object
await base.findOneAndUpdate({ baseURL: contentObject.basURL },
{
"links.subPageURLs": {
[contentObject.subPage]: contentObject.links.subPageurls[contentObject.subPage]
},
"content.subPageContent": {
[contentObject.subPage]: contentObject.content.subPageContent[contentObject.subPage]
}
}
}
},
{ upsert: true }, (err, doc) => {
console.log(err)
db.close()
})
My final product would look something like this:
subPages: {
contactus: ["www.example.com", "www.website.com/subpage", "etc..."],
aboutus: ["www.example.com", "www.website.com/subpage", "etc..."],
news: ["http://news.example.com", "www.newsexample.com", "etc..."]
}
}
Then if i had another page to add, i would add it to the subPages object
login: ["login.example.com", "signup.example.com"]

Answer 1

To append an object to another object you can try to do this.
const a = { name:`Bob`, age:30 }
const b = { gender:`M`, age:45 }
const c = { ...a, ...b } //this will merge "a" with c
console.log(c) // will print { name:`Bob`, age:45, gender:`M` }
So it will work like that all properties in right object will overridden by left object and the left object properties does n't exists in right object will be appended.