Advanced Array Summation in AngularJS
In AngularJS, summing array properties can be a common task. A basic approach involves iterating through the array and accumulating the property values. However, this method becomes tedious when faced with multiple arrays and varying property names.
To address this, a more flexible and reusable solution is desired, one that allows for convenient summation of any array property. This can be achieved using the reduce() method, which provides a powerful way to aggregate array values.
Consider the following example:
$scope.traveler = [ { description: 'Senior', Amount: 50}, { description: 'Senior', Amount: 50}, { description: 'Adult', Amount: 75}, { description: 'Child', Amount: 35}, { description: 'Infant', Amount: 25 }, ];
To sum the 'Amount' property of the traveler array using reduce(), we can write a method as follows:
$scope.sum = function(items, prop){ return items.reduce( function(a, b){ return a + b[prop]; }, 0); };
In this method, we use the reduce() method with a callback function that accepts two arguments: the accumulated value (a) and the current element (b) of the array. Within the callback, we access the property we want to sum (prop) and add it to the accumulated value.
To apply this method to our traveler array, we can do the following:
$scope.travelerTotal = $scope.sum($scope.traveler, 'Amount');
Using this approach, we can easily sum property values of any array in our AngularJS application. By defining a reusable method, we avoid redundant code and ensure consistency in our summation calculations.
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