Reading out a JSON object in twig

Question

I am trying to get data out of a JSON object but that isn't working quite well.

This is how I made my JSON object (I used Twig for this project) and later try to reach it to get the value from it:

<script>
    let data = [
        {% for entry in markers %}
        {"name": "{{ entry.title }}", "address": "{{ entry.address.address }}", "lat": "{{ entry.address.lat }}", "lng": "{{ entry.address.lng }}"},
        {% endfor %}
    ];
    let json = JSON.parse(data); //it already goes wrong here.
    alert(json.name);
</script>

This is how my object looks:

(6) [{…}, {…}, {…}, {…}, {…}, {…}]
0:
address: "Tilburg, Nederland"
lat: "51.56059600"
lng: "5.09191430"
name: "Tilburg"
__proto__: Object
1:
address: "Amsterdam, Nederland"
lat: "52.36798430"
lng: "4.90356140"
name: "Amsterdam"
__proto__: Object
2:
address: "Eindhoven, Nederland"
lat: "51.44164200"
lng: "5.46972250"
name: "eindhoven"
__proto__: Object
3:
address: "Drenthe, Nederland"
lat: "52.94760120"
lng: "6.62305860"
name: "drenthe"
__proto__: Object
4:
address: "Limburg, Nederland"
lat: "51.44272380"
lng: "6.06087260"
name: "limburg"
__proto__: Object
5:
address: "Arnhem, Nederland"
lat: "51.98510340"
lng: "5.89872960"
name: "test"
__proto__: Object
length: 6
__proto__: Array(0)

I think my error is in the part where I make the object. But I don't know what I did wrong.

---

edit: I forgot to add the error message. This is what the console tells me in chrome:

VM9133:1 Uncaught SyntaxError: Unexpected token o in JSON at position 1 at JSON.parse () at maps:63 (anonymous) @ maps:63