Reduce javascript object

Question

I have this javascript object :

{
    {
        long_name: "10",
        types: [
            0: "street_number"
        ],
    },
    {
        long_name: "street",
        types: [
            0: "route"
        ],
    },
    {
        long_name: "Paris",
        types: [
            0: "locality"
        ],
    },
    ...
}

And I want to flatten it and have something like :

{
    street_number: "10",
    route: "street",
    locality: "Paris",
    ...
}

I am using ES6, but can't manage to flatten it this much, All I've succeeded to do is having :

{
    {street_number: "10"},
    {route: "street"},
    {locality: "Paris"},
    ...
}

Here is what I Tried :

const flattenedObject = originalObject.map(flatten);
...
function flatten(element) {
    let obj = {};
    obj[element.types[0]] = element.long_name;

    return obj;
}

Thanks for any help.

You can use something like this: lodash.com Lodash has a big set of pretty useful functions, including flatten. — smddzcy
– smddzcy, Commented Dec 23, 2016 at 12:14
Put let obj = {} outside of the flatten method, since this is the object you want to extend. Currently, you're building a new one for each array item. — Oliver Hader
– Oliver Hader, Commented Dec 23, 2016 at 12:23
@SamedDüzçay but this has nothing do with the kind of flattening that lodash _.flatten does. — user663031
– user663031, Commented Dec 23, 2016 at 12:29

Nina Scholz · Accepted Answer · 2016-12-23 12:29:27Z

3

You could use Array#reduce with a computed property and the first element only from the array.

The key feature is Object.assign for adding properties to the result object.

The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.

var data = [{ long_name: "10", types: ["street_number"], }, { long_name: "street", types: ["route"], }, { long_name: "Paris", types: ["locality"], }],
    object = data.reduce((r, a) => Object.assign(r, { [a.types[0]]: a.long_name }), {});

console.log(object);

edited Dec 23, 2016 at 12:29

answered Dec 23, 2016 at 12:17

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

sac Dahal Over a year ago

what does this do data.reduce((r, a)

Nina Scholz Over a year ago

@sacDahal, Array#reduce takes an array and returns a value by processing all items of the array.

user663031 · Accepted Answer · 2016-12-23 12:29:03Z

2

All I've succeeded to do is having:

{
  {street_number: "10"},
  {route: "street"},
  {locality: "Paris"},
  ...
}

I don't how you "succeeded" in getting that, since no such kind of object exists in JS (nor does your original object). Did you mean to put [] around it instead of {} (in other words, is it an array of little objects)? If so, then combine with

 Object.assign({}, ...littleObjects)

By the way, you can call this "flattening" if you want, but it will be confusing, since it's quite different from what people usually refer to as "flattening" (meaning to collapse nested arrays).

answered Dec 23, 2016 at 12:29

user663031

Collectives™ on Stack Overflow

Reduce javascript object

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related