Getting the value of a js object key

Question

I need to be able to get the value of an object key. When I console.log(event); a returned object, I am getting:

MessageEvent {
    ports: Array[0], 
    data: "{
        "event":"playProgress",
        "data":{
            "seconds":0.419,
            "percent":0.002,
            "duration":177.813
        }
    }"
}

I can't seem to get to value of the data.percent with console.log(event.data.percent). What am I doing wrong?

console.log(event.data.data.percent) ? – Eduardo Wada Mar 20 '15 at 22:02 — Eduardo Wada, Mar 20 '15 at 22:02

score 4 · Accepted Answer · edited May 23 '17 at 10:10

4

It looks like event.data is actually a string, and not a nested object. With a "reasonably modern" browser, you can:

var data = JSON.parse(event.data);
console.log(data.percent);

More discussion on JSON.parse can be seen at this previous stackoverflow answer.

edited May 23 '17 at 10:10

Community

1
1

answered Mar 20 '15 at 22:03

lsowen

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Thanks! I got confused over the data in the data. – superUntitled Mar 20 '15 at 23:21

score 0 · Answer 2 · answered Mar 20 '15 at 22:04

Remove the quotes around your first data object

MessageEvent {
    ports: Array[0], 
    data: {
        "event":"playProgress",
        "data":{
            "seconds":0.419,
            "percent":0.002,
            "duration":177.813
        }
    }
}

By leaving them in your creating a string rather then an obj

Alessandro Incarnati · Answer 3 · 2015-03-20T22:29:42.050

You need to go down another level in your MessageEvent object to access the subobject data of the first data object. In order to console.log you don't even need to stringify and then parse the object, like in this case.

Try below:

var MessageEvent = {
    ports: Array[0], 
    data: {
        "event":"playProgress",
        "data":{
            "seconds":0.419,
            "percent":2.002,
            "duration":177.813
        }
    }
};

console.log(MessageEvent.data.data.percent);

JSFiddle: http://jsfiddle.net/a_incarnati/em3afkov/

Getting the value of a js object key

3 Answers3