How can I push an object in an array of objects to an array within another array of object?-CodePudding

I have a variable parks with the following:

let parks = [
  { id: 1, park_name: 'Average Park', review: [] },
  { id: 2, park_name: 'Better Park', review: [] },
  { id: 3, park_name: 'Cooler Park', review: [] },
  { id: 4, park_name: 'Dull Park', review: [] }
]

And another variable review with the following:

let review = [
  { id: 1, park_id: 1, comment: "It's an okay park. Seen better" },
  { id: 2, park_id: 1, comment: "Ehh, it's alright" },
  { id: 3, park_id: 2, comment: "It's pretty decent" },
  { id: 4, park_id: 3, comment: "Good not great" }
]

What I want to achieve is adding the review object to parks.review based on park_id == parks.id. Basically I want is this:

[
  { id: 1, park_name: 'Average Park', review: [{ id: 1, park_id: 1, comment: "It's an okay park. Seen better" },  { id: 2, park_id: 1, comment: "Ehh, it's alright" }] },
  { id: 2, park_name: 'Better Park', review: [{ id: 3, park_id: 2, comment: "It's pretty decent" }] },
  { id: 3, park_name: 'Cooler Park', review: [{ id: 4, park_id: 3, comment: "Good not great" }] },
  { id: 4, park_name: 'Dull Park', review: [] }
]

What is the best approach to take?

CodePudding user response：

nested for of will be the easiest and straightforward way for scanning 2 arrays simultaneously and so something.

You can also do it in with a single loop and use _.find or filter to make the code look more elegant

let parks = [
  { id: 1, park_name: 'Average Park', review: [] },
  { id: 2, park_name: 'Better Park', review: [] },
  { id: 3, park_name: 'Cooler Park', review: [] },
  { id: 4, park_name: 'Dull Park', review: [] }
];
let reviews = [
  { id: 1, park_id: 1, comment: "It's an okay park. Seen better" },
  { id: 2, park_id: 1, comment: "Ehh, it's alright" },
  { id: 3, park_id: 2, comment: "It's pretty decent" },
  { id: 4, park_id: 3, comment: "Good not great" }
];

for(let park of parks) {
  for(let review of reviews) {
    if(park.id === review.park_id) {
      park.review.push(review);
    }
  }
}

console.log(parks);

CodePudding user response：

You could iterate both arrays only once.

Take parks to get a reference by id to the park and add all reviews to their referenced park.

const
    parks = [{ id: 1, park_name: 'Average Park', review: [] }, { id: 2, park_name: 'Better Park', review: [] }, { id: 3, park_name: 'Cooler Park', review: [] }, { id: 4, park_name: 'Dull Park', review: [] }],
    review = [{ id: 1, park_id: 1, comment: "It's an okay park. Seen better" }, { id: 2, park_id: 1, comment: "Ehh, it's alright" }, { id: 3, park_id: 2, comment: "It's pretty decent" }, { id: 4, park_id: 3, comment: "Good not great" }],
    parkIds = Object.fromEntries(parks.map(o => [o.id, o]));

review.forEach(o => parkIds[o.park_id].review.push(o));

console.log(parks);

.as-console-wrapper { max-height: 100% !important; top: 0; }

CodePudding user response：

Off the top of my head I would do something like this:

let parks = [
  { id: 1, park_name: "Average Park", review: [] },
  { id: 2, park_name: "Better Park", review: [] },
  { id: 3, park_name: "Cooler Park", review: [] },
  { id: 4, park_name: "Dull Park", review: [] },
];

let reviews = [
  { id: 1, park_id: 1, comment: "It's an okay park. Seen better" },
  { id: 2, park_id: 1, comment: "Ehh, it's alright" },
  { id: 3, park_id: 2, comment: "It's pretty decent" },
  { id: 4, park_id: 3, comment: "Good not great" },
];

const combined = parks.map((park) => ({
  ...park,
  review: reviews.filter((review) => review.park_id === park.id),
}));