I exptect that mandrill_events only contains one object. How do I access its event-property?
var req = { mandrill_events: '[{"event":"inbound","ts":1426249238}]' }
I exptect that mandrill_events only contains one object. How do I access its event-property?
var req = { mandrill_events: '[{"event":"inbound","ts":1426249238}]' }
 
    
    var req = { mandrill_events: '[{"event":"inbound","ts":1426249238}]' }
console.log(Object.keys(req)[0]);
Make any Object array (req), then simply do Object.keys(req)[0] to pick the first key in the Object array.
 
    
    To answer your titular question, you use [0] to access the first element, but as it stands mandrill_events contains a string not an array, so mandrill_events[0] will just get you the first character, '['.
So either correct your source to:
var req = { mandrill_events: [{"event":"inbound","ts":1426249238}] };
and then req.mandrill_events[0], or if you're stuck with it being a string, parse the JSON the string contains:
var req = { mandrill_events: '[{"event":"inbound","ts":1426249238}]' };
var mandrill_events = JSON.parse(req.mandrill_events);
var result = mandrill_events[0];
 
    
    I'll explain this with a general example:
var obj = { name: "John", age: 30, city: "New York" };
var result = obj[Object.keys(obj)[0]];
The result variable will have the value "John"
 
    
    the event property seems to be string first you have to parse it to json :
 var req = { mandrill_events: '[{"event":"inbound","ts":1426249238}]' };
 var event = JSON.parse(req.mandrill_events);
 var ts =  event[0].ts
 
    
    '[{"event":"inbound","ts":1426249238}]' is a string, you cannot access any properties there. You will have to parse it to an object, with JSON.parse() and then handle it like a normal object
 
    
    Assuming thant the content of mandrill_events is an object (not a string), you can also use shift() function:
var req = { mandrill_events: [{"event":"inbound","ts":1426249238}] };
var event-property = req.mandrill_events.shift().event;
