How to add values to objects similar to push(array) using forEach

Question

I'm currently struggling to add some numbers to an object like we do for arrays using push().

I have an array that looks like this:

$scope.order = [
  {sequenceNumber:1},
  {sequenceNumber:2},
  {sequenceNumber:3}  
];

And i'm using a forEach method to add the numbers to an object "newOrder"

var newOrder = {};

angular.forEach($scope.order, function(orderValue) {
  newOrder = orderValue.sequenceNumber;
});

However...this doesnt return the result that i want

I want "newOrder" to look like this:

var newOrder = {
  1: 1,
  2: 2,
  3: 3
};

Value = position of the array

Key = sequenceNumber

Mihai Potra · Accepted Answer · 2019-01-11 17:39:50Z

1

You could use Array.prototype.reduce in this case, like so:

var newOrder = $scope.order.reduce(function(acc, item, index) {
  acc[item.sequenceNumber] = index;
  return acc;
}, {});

Or shorter equivalent:

var newOrder = $scope.order.reduce((acc, {sequenceNumber}, index) => {
  acc[sequenceNumber] = index;
  return acc;
}, {});

answered Jan 11, 2019 at 17:39

Mihai Potra

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