Javascript Reduce on Object

Question

I have a javascript object

0:
{
  firstName: "John",
  lastName: "Doe",
  score: 50,
}

1:
{
  firstName: "Jane",
  lastName: "Doe",
  score: 22,
};
.
.
.
more...

I want to sum their scores using reduce. I know it can be done with for loop to turn that into scoreArray and reduce. Is there any efficient way to use reduce on object data so I don't need to do use for loop or create unnecessary array?

You already have an array. Otherwise there wouldn't be a `.reduce()` to use in the first place. — Andreas, Aug 16 '19 at 12:02
The kind of "Object" you're talking about suggest you're talking about an **array of objects** instead, if so, you can just use `reduce` over it. — briosheje, Aug 16 '19 at 12:03

score 0 · Answer 1 · answered Aug 16 '19 at 12:04

0

You can just use reduce on the array of objects:

let arr = [
  { firstName: "John", lastName: "Doe", score: 50 },
  { firstName: "Jane", lastName: "Doe", score: 22, }
];

let sum = arr.reduce((acc, obj) => acc + obj.score, 0);
console.log(sum);

answered Aug 16 '19 at 12:04

Turtlefight

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Javascript Reduce on Object

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