Array undefined javascript

Question

Hello my problem is that i get undefined , when trying to accsess the array length, but everything works fine when i try to access only the array.

this above do not works ->

console.log(this.ref_number_response[0].info.length);

This works ->

console.log(this.ref_number_response);

and this is the whole

check_ref_number: function () {

 this.ref_number_response = [];

 axios.get('/is_referenceNumber_free/'+this.ref_number)
 .then(response => this.ref_number_response.push({ 
   info: response.data

}));


 console.log(this.ref_number_response[0].info.length);

 Event.$emit('reference_added', this.ref_number_response);

},

Possible duplicate of [How do I return the response from an asynchronous call?](https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) — CBroe, Sep 18 '17 at 08:56
You should check what `ref_number_response` contains and type. — bhansa, Sep 18 '17 at 08:57

score 0 · Answer 1 · answered Sep 18 '17 at 09:02

0

Emit the event after you recieve the data:

check_ref_number: function () {
 axios.get('/is_referenceNumber_free/'+this.ref_number)
 .then(response => Event.$emit('reference_added',[{info:response.data}]));
}

The problem is that you are getting the data asynchronously, and trying to use the data before it is ready.

answered Sep 18 '17 at 09:02

Eladian

958
10
29

what error are you getting? add a catch clause and print the error. – Eladian Sep 18 '17 at 23:34

score 0 · Answer 2 · answered Sep 18 '17 at 09:09

0

You said you are trying to access the the array length, but

this.ref_number_response

is the array, so the only way this console.log(this.ref_number_response[0].info.length); is going to work ( you're trying to get the info property from first element of the array length not the actual array length ) is if info were an array as well. So you'd probably need to do something like:

console.log(this.ref_number_response.length);

answered Sep 18 '17 at 09:09

Alejandro Camba

978
10
25

While this is true, the code provided above will still fail regardless of this change. – Eladian Sep 18 '17 at 13:30
what error do you get after the changes? undefined? null value? ( note that the guy above is also right ) – Alejandro Camba Sep 18 '17 at 13:34
This does not work, I have expose the right way to the length but I am missing something else – Iliyan Iliev Sep 18 '17 at 16:13

Array undefined javascript

2 Answers2