Snapshot key not working with value findindex?

Question

How to make work findIndex depending of a snapshotkey ?it's not working with the variable but actually work with a manual string ?!

 this.state.data =     Object {

  "date_add": 1574177488383,
  "date_upd": 1574178141010,
  "question": "1",
"key": "123455566",
}
ref.on('child_changed', snapshot => {
          var key = snapshot.key


          console.log('the key', key) // return 123455566
})

actually not working like this :

      var foundIndex = this.state.data.findIndex(x => x.key == key);

but work like this

 var foundIndex = this.state.data.findIndex(x => x.key == '123455566');

what code you need ? it's a simple findindex who work with string but not with an object what can i add ? — manyouuwx, Nov 19 '19 at 15:52

score 0 · Answer 1 · answered Nov 19 '19 at 16:05

0

var key = "123456";
var data = [{"key":"123456"},{"key": "123"},{"key":  "12"}, {"key":"1"}]
var foundIndex = data.findIndex(x => x.key == key);
console.log(foundIndex); //0
var ind = data.findIndex(x => x.key == '12'); 
console.log(ind); //2

answered Nov 19 '19 at 16:05

PragJh

41
1
4

it's already work when i write it as string but not when i use a KEY from an object – manyouuwx Nov 19 '19 at 16:10

score 0 · Answer 2 · answered Nov 19 '19 at 16:06

0

You should use:

var foundIndex = this.state.data.findIndex(x => x.key == x.key);

Im not sure what you are trying to get but, you usefindindex to get the index of a value.

You can see multiple examples here:

Get the index of the object inside an array, matching a condition

Find index of object in javascript by a value

Also the docs:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex

answered Nov 19 '19 at 16:06

Peter Haddad

78,874
25
140
134

what ? i try to get by specific key it's working when i write it but not from object ? – manyouuwx Nov 19 '19 at 16:09
Did you enter any of these links? – Peter Haddad Nov 19 '19 at 16:14
yes and you dont understand i try to get the index of the value depending of my key ? why do you use x.key == x.key ? where is the specific variable key here ? – manyouuwx Nov 19 '19 at 16:21
I thought key is the whole object – Peter Haddad Nov 19 '19 at 16:23
Inside `child_changed` add `console.log(this.state.data.findIndex(x => x.key == key));` because if you are using it outside `child_changed` then `key` would be null because it is asychronous – Peter Haddad Nov 19 '19 at 16:25
it is inside actually , the fact it's working well with i write the manual return of my variable ! but not directly with it – manyouuwx Nov 19 '19 at 16:27
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/202661/discussion-between-peter-haddad-and-manyouuwx). – Peter Haddad Nov 19 '19 at 16:27
Did you try the answer? – Peter Haddad Nov 25 '19 at 17:18

Snapshot key not working with value findindex?

2 Answers2

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