StevieB StevieB - 1 month ago 15
AngularJS Question

JS How to use reduce on array containing multiple numerical values

I have an array like this.

[{
PropertyOne : 1,
PropertyTwo : 5
},
{
PropertyOne : 2,
PropertyTwo : 5
},...]


And I want to end up with an array like this which aggregates all the columns of this array to end up like this.

[{
PropertyOne : 6,
PropertyTwo : 10
}}


If it was a single column I know I could use .reduce but can't see how I could do with multiple columns ?

Answer
var array = [{
  PropertyOne : 1,
  PropertyTwo : 5
},
{
  PropertyOne : 2,
  PropertyTwo : 5
}];
var reducedArray = array.reduce(function(accumulator, item) {
  // loop over each item in the array
  Object.keys(item).forEach(function(key) {
    // loop over each key in the array item, and add its value to the accumulator.  don't forget to initialize the accumulator field if it's not
    accumulator[key] = (accumulator[key] || 0) + item[key];
  });

  return accumulator;
}, {});
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