Using reduce to group array of objects

Question

I am having a crazy hard time figuring this out, maybe because I almost never use the reduce method and I have been looking at this way too long but all I am trying to do here is group together an array of objects based on the product title.

const products = [
    {
        id: 1,
        title: 't-shirt'
    },
    {
        id: 2,
        title: 't-shirt'
    },
    {
        id: 3,
        title: 'jeans'
    }
]

const linked_products = products.reduce((prevProduct, product) => {
    
}, [])

products.forEach(product => {
  // this is an array of objects
  // it's an array of objects with the same title
  product.linked_products = linked_products
})

Expected Output:

products = [
  {
    id: 1,
    title: 't-shirt',
    // here is the new property
    linked_products: [
      { id: 2, title: 't-shirt'}
    ]
  },
  {
    id: 2,
    title: 't-shirt',
    linked_products: [
      { id: 1, title: 't-shirt'}
    ]
  },
  {
    id: 3,
    title: 'jeans',
    linked_products: []
  }
]

malarres · Accepted Answer · 2022-07-14 11:56:40Z

3

Does it have to be with reduce?

A forEach would fit your need pretty well:

const products = [
    {
        id: 1,
        title: 't-shirt'
    },
    {
        id: 2,
        title: 't-shirt'
    },
    {
        id: 3,
        title: 'jeans'
    }
]


products.forEach( item => {
  item.linked_products = products.filter( linked => linked.id != item.id && linked.title == item.title ).map(({id,title,...rest}) => ({id,title}) )
} )

console.log(products)

answered Jul 14, 2022 at 11:56

malarres

2,9481 gold badge24 silver badges37 bronze badges

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

1 Comment

dbzx10299 Over a year ago

Thanks that did work, I was trying to figure this out for educational reasons though with reduce because it's bothering me like crazy I can't get it to work

Pratik Wadekar · Accepted Answer · 2022-07-14 12:16:02Z

1

UPDATED CODE

const products = [
  {
    id: 1,
    title: 't-shirt'
  },
  {
    id: 2,
    title: 't-shirt'
  },
  {
    id: 3,
    title: 'jeans'
  }
]


const mappedProducts = products.map(product => {
  const linkedProducts = products.filter(prod => prod.id !== product.id && prod.title === product.title);
  return {
    ...product,
    linkedProducts
  }
})

console.log(mappedProducts)

edited Jul 14, 2022 at 12:16

answered Jul 14, 2022 at 11:45

Pratik Wadekar

1,2749 silver badges19 bronze badges

7 Comments

dbzx10299 Over a year ago

hey thanks a lot, I just tried this, it is almost working. If you look at my expected output it's not quite working though the way I expect.

DecPK Over a year ago

This is not what OP wants...

Pratik Wadekar Over a year ago

Changed my code now

dbzx10299 Over a year ago

@Pratik Wadekar Super close, the only thing is the linked_products should be pointing only to other products with the same title property. Here they point to themselves

Pratik Wadekar Over a year ago

Your input contains no test a but the output does. How come ?

|

Collectives™ on Stack Overflow

Using reduce to group array of objects

2 Answers 2

1 Comment

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related