How to join multi arrays from Object properties in Javascript?

Question

I am using AngularJS and I have a problem as below:
I have created an Object whose properties are arrays. For example:

$scope.myObject = {
   import: [ object1, object2,...,objectN ],
   export: [ object1', object2',...,objectN' ],
   ...
}

Now I want to create a new array which concats all arrays from myObject properties so that I can display them in HTML view with ng-repeat.
This is my Plnk sample code: http://plnkr.co/edit/Ca8OX7kX8wV8JmRYJCzS?p=preview
Please help me. Thanks.

Michel · Accepted Answer · 2015-03-17 02:17:58Z

1

With underscore or lodash :

_.flatten(_.values($scope.myObject));

See fiddle

I've added also a plain JS (EcmaScript 5+) method :

$scope.myObjectJS = [];
Object.keys($scope.myObject).forEach(function(key) {
   $scope.myObjectJS = $scope.myObjectJS.concat($scope.myObject[key]);  
});

The fact that I use Object.keys(obj) instead of for (var key in obj) exempts us to check for hasOwnProperty.

edited Mar 17, 2015 at 2:17

answered Mar 16, 2015 at 15:14

Michel

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2 Comments

Huy Do Over a year ago

Thank you, but it seems just correct with simple array/objects. In my case, it still return a blank array. Maybe it concats too soon when my properties still not get the results back from server?

Michel Over a year ago

The plnkr you provided does not reflect the question. In the template, you are ng-repeating over a variable called array that does not even exist. Furthermore, I don't see any concat method of your data.

Tyler McGinnis · Accepted Answer · 2015-03-17 00:55:09Z

1

If I understand your question right this should work.

var newArr = [];
for(var key in $scope.myObject){
  newArr = newArr.concat($scope.myObject[key]);
}

edited Mar 17, 2015 at 0:55

answered Mar 16, 2015 at 15:08

Tyler McGinnis

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2 Comments

radiaph Over a year ago

Need to assign result of concat() back into newArr.

Huy Do Over a year ago

Thanks but it returns the blank array. I have created Plnk to show my sample code: plnkr.co/edit/Ca8OX7kX8wV8JmRYJCzS?p=preview

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