Loop through object with multidimensional array

Question

I use promises in angular to get some data from the server. In promises success I do

promise.success(function (data, status) {                          
  for (i = 0; i <= data.data.length; i++){
    $scope.anArray[i]  = data.data[i][1] ;
  }   
}

I do this because data that came from the server have this structure

{"result":"answered","data":[["jake","508"],["amir","602"],["ben","450"]]}

and I ONLY want to get the numbers 508 , 602 and 450. But I always get the same error TypeError: Cannot read property '0' of undefined reffering to this line : $scope.anArray[i] = data.data[i][0] ;.

Those numbers are feeded to a library to create a chart. Sometimes the chart is created, some times is not. Even if it is created, the same error is always there.

I dont know how to fix that error and getting the chart to be always created without any problems. Looks like the code doesnt like the data.data[i][0] structure, having a simple array like data.data[i] doesnt create an error.

What should I do?

Thanks

use angular.forEach() is way cleaner and already in the lib core. docs.angularjs.org/api/ng/function/angular.forEach — Filippo oretti
– Filippo oretti, Commented May 12, 2016 at 16:10
@sbaaaang I chose Paarths answer as the right one because it takes the minimum ammount of editing to fix my code. But your suggestion is also very nice, I even forgot there is the forEach. Thanks for the help. — slevin
– slevin, Commented May 12, 2016 at 16:21
of course you're welcome, just remember angular.forEach() is exactly a for loop cleaner and more easy to use, makes no sense to use plain js when you have that ;) — Filippo oretti
– Filippo oretti, Commented May 15, 2016 at 14:04

Paarth · Accepted Answer · 2016-05-12 16:22:07Z

1

Your for loop has an extra execution. You've initialized i to 0 but you've also used <= which means you are going to execute on array[array.length] which is out of bonds. That returns undefined and when you try to access the [0] index on that undefined you get that error.

Change to

for (i = 0; i < data.data.length; i++){

If you're able to do assignment personally I would go with

$scope.anArray = data.data.map(entry => entry[1]);

and skip the for loop entirely. Note if you want to avoid lambdas this would be

$scope.anArray = data.data.map(function(entry) { return entry[1]; });

edited May 12, 2016 at 16:22

answered May 12, 2016 at 16:12

Paarth

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1 Comment

slevin Over a year ago

Yes, I ment to write $scope.anArray[i] = data.data[i][1] ;, I edited my question, so you can erase that part about 0 from your answer too. Also... DUDE, you are right, all I had to do was to erase the = from my for. Thanks

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