firebase get child value javascript
The value you extract is a regular JavaScript/JSON object,
so you can access its members as you would do with any other JavaScript object.
Your 1, 2, 3 level keys will be converted to an array by Firebase,
which means it adds a null item at the start of that array.
For more about that, see: Firebase database returns null at beginning of each new node
To loop over all child nodes under the child of patterns that was changed and get the players whose status is 0 you'd do something like:
var ref = firebase.database().ref("games/" + gameId + "/patterns");
ref.on("child_changed", function(snapshot){
snapshot.forEach(function(child) {
if (child.val() && child.val().status == "0") {
console.log(child.val().player);
});
});
});