match between two array of objects javascript

Question

I'm building an api to add orders for a store, in the function I receive identity attributes (clientId...) and an array of the order as so:

order = [{packageId,quantity},...]

I then get the prices of the packages from to DB the get the latest price as so :

packagePrice= [{packageId,unitPrice}, ...(all the packages that are needed)]

my problem is that how could I reconstruct the order array to match each package with its price as so:

order=[{packageId, quantity, UnitPrice}, ...( all other packages)]

Thank you

IT goldman · Answer 1 · 2022-10-07T11:21:06.110

1

A nested loop

var packageId = 1277;
var quantity = 2;
var unitPrice = 1.00

var order = [{packageId,quantity}]

var packagePrice= [{packageId,unitPrice}]

order.forEach(function(item) {
  item.unitPrice = packagePrice.find(function(item2) {
    return item2.packageId == item.packageId
  }).unitPrice
})

console.log(order)

edited Oct 07 '22 at 11:21

answered Oct 07 '22 at 08:23

IT goldman

14,885
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Why use `map()` if you're going to discard the result of the `map()` operation anyway? – Robby Cornelissen Oct 07 '22 at 08:25
No reason just was a harmless error. – IT goldman Oct 07 '22 at 08:33
The return of your `find()` function is incorrect. You're assigning instead of comparing. – Robby Cornelissen Oct 07 '22 at 08:55

Robby Cornelissen · Accepted Answer · 2022-10-07T08:32:18.760

1

Just adding the unitPrice to the existing order array would be:

order.forEach(
  v1 => v1.unitPrice = packagePrice.find(
    v2 => v1.packageId === v2.packageId
  )?.unitPrice
);

edited Oct 07 '22 at 08:32

answered Oct 07 '22 at 08:23

Robby Cornelissen

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22
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score 1 · Answer 3 · answered Oct 07 '22 at 08:48

There are more than on way to handle this. From a maintainablility and readability stand point i would do it it in two steps :

1 - Convert the array of package [{packageid,price}], to a map {packageid:price} :

This would make it easyer to use elsewere in the code Here is a way to do it: https://stackoverflow.com/a/26265095/8541886

2 - map over the order items

You could use Array.map() or a simple for loop to add the prices to the order array

Here is how the code would look :

// get the unit prices as a map
const unitPrices = packagePrice.reduce( 
   (prices,pakageprice) => {
      prices[pakageprice.packageId] = pakageprice.unitPrice
      return prices
   },
   {} // initial value for unit prices
)

// add it to the order array
const ordersWithPrices = orders.map( order => {
    order.unitPrice = unitPrices[order.packageId]
    return order
} )

score 0 · Answer 4 · answered Oct 07 '22 at 09:02

import { merge } from "lodash";

var object = [{ b: 2, c: 3 }];
var other = [{ b: 2, e: 5 }];

console.log(merge(object, other));

Use Lodash merge that will allow you to merge two arrays into one.

https://codesandbox.io/s/lodash-playground-forked-rjfu80?file=/src/index.js:0-129

match between two array of objects javascript

4 Answers4