'undefined' error when trying to access Firebase DB using JavaScript

Question

This is what I have saved in DB

This is my code which I used to try to access the data.

The goal is to get the value of the 1st id

var ref = db.ref("server/events/data");
ref.once("value", function(snapshot) { 

  var ids = snapshot.val();
  console.log(ids.id);

});

What am I missing ?

Please post the full exception details

J.N.
– J.N.

2017-06-11 06:34:11 +00:00
Commented Jun 11, 2017 at 6:34 — J.N.
– J.N., Commented Jun 11, 2017 at 6:34

Dinesh undefined · Accepted Answer · 2017-06-11 06:36:11Z

2

You should specify the index to access

  var ref = db.ref("server/events/data");
    ref.once("value", function(snapshot) { 

      var ids = snapshot.val();
      console.log(ids[0].id);

    });

answered Jun 11, 2017 at 6:36

Dinesh undefined

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1 Comment

Dinesh undefined Over a year ago

@Suhaib you can use for loop or forEach for example check Frank answer

Frank van Puffelen · Accepted Answer · 2017-06-11 06:38:07Z

1

Alternative to Dinesh' answer is looping over all results:

var ref = db.ref("server/events/data");
ref.once("value", function(snapshot) { 
  snapshot.forEach(function(childSnapshot) {
    var value = childSnapshot.val();
    console.log(value.id);
  });
});

Or accessing only a specific index:

var ref = db.ref("server/events/data/0");
ref.once("value", function(snapshot) { 
  var value = snapshot.val();
  console.log(value.id);
});

answered Jun 11, 2017 at 6:38

Frank van Puffelen

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1 Comment

Suhaib Over a year ago

Awesome. That's what I was looking for. Thanks for looking beyond my specific question

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