Recursively unpacking a javascript object

Question

I'm seeing a React course, we were studying fundamentals of javascript for a while. We saw how to access the content of an object and display it in console. My solution for the problem of displaying an unknown object was the following:

function unpackObject(obj, tabs = '') {
    const props = Object.getOwnPropertyNames(obj);

    let v;
    props.forEach(p => {
        v = obj[p];
        //v = Object.getOwnPropertyDescriptor(obj, p).value; | side question: is it better?

        if (v instanceof Object) {
            console.log(`${tabs}${p} ${Object.prototype.toString.call(v)}`);
            if (v instanceof Array)
                v.forEach((x, i) => console.log(`${tabs}\t[${i}]: ${x}`));
            else
                unpackObject(v, `${tabs}\t`);
        } else
            console.log(`${tabs}${p}: ${v}`);
    });
}

// Testing code:
const testObject = {
    name: 'Miguel',
    surname: 'Avila',
    age: undefined, //LOL
    marital_status: 'Single',
    hobbies: ['Write Code', 'Watch YT Videos', 'etc. idk'],
    contact: {
        phones: ['xxxxxxxxxx', 'xxxxxxxxxx'],
        address: 'unknown'
    }
};

unpackObject(testObject);

My questions are: Can this code be faster and/or shorter? Are there any tricks capable of improving it for massive objects? (I mean, I fear recursion because when it goes wrong it's a big deal).

Answer 1

Try this testObject. You may want to do something to test for recursion, e.g. an array or map that tracks objects that you have already seen.

function unpackObject(obj, tabs = '') {
    const props = Object.getOwnPropertyNames(obj);

    let v;
    props.forEach(p => {
        v = obj[p];
        //v = Object.getOwnPropertyDescriptor(obj, p).value; | side question: is it better?

        if (v instanceof Object) {
            console.log(`${tabs}${p} ${Object.prototype.toString.call(v)}`);
            if (v instanceof Array)
                v.forEach((x, i) => console.log(`${tabs}\t[${i}]: ${x}`));
            else
                unpackObject(v, `${tabs}\t`);
        } else
            console.log(`${tabs}${p}: ${v}`);
    });
}

// Testing code:
let testObject = {
    name: 'Miguel',
    surname: 'Avila',
    age: undefined, //LOL
    marital_status: 'Single',
    hobbies: ['Write Code', 'Watch YT Videos', 'etc. idk'],
    contact: {
        phones: ['xxxxxxxxxx', 'xxxxxxxxxx'],
        address: 'unknown'
    }
};
testObject.object = testObject;

unpackObject(testObject);

This actually works better than I expected. It eventually crashes and displays with an error message.