Compare 2 arrays of objects (with parameters) and return equals

Question

I have this 2 arrays:

var a = [{cod: 123, brand: 'Audi', model: 'A3', price: 15000, km: 20000}, 
         {cod: 456, brand: 'BMW', model: 320, price: 20000, km: 30000}]
var b = [{brand: 'Audi', model: 'A3', price: 100000, km: 100000}]

What I want to do is, compare both arrays, and return the object from a that as the same brand and model as b and only if the maximum price and km don't exceed 100000. If the Audi on a had a price of 120000, then it wouldn't return anything.

EDIT: Nina answer worked perfectly. But if one of the items on filter is empty it won't return anything. How can i ignore empty values and only compare the others?

Please include attempted solutions, why they didn't work, and the expected results. That would really help us to figure out the issue with your code. — palaѕн, Dec 29 '17 at 13:55
Possible duplicate of [How to compare arrays in JavaScript?](https://stackoverflow.com/questions/7837456/how-to-compare-arrays-in-javascript) — serkan, Dec 29 '17 at 14:01

score 2 · Accepted Answer · answered Dec 29 '17 at 14:02

2

You could filter the array with the filter values.

var array = [{ cod: 123, brand: 'Audi', model: 'A3', price: 15000, km: 20000 }, { cod: 456, brand: 'BMW', model: '320', price: 20000, km: 30000 }],
    filter = [{ brand: 'Audi', model: 'A3', price: 100000, km: 100000 }],
    result = array.filter(a => filter.some(b => a.brand === b.brand && a.model === b.model && a.price <= b.price && a.km <= b.km));

console.log(result);

answered Dec 29 '17 at 14:02

Nina Scholz

376,160
25
347
392

Im accepting this one since it was the first to comment :p it worked perfectly with that array. I just need to change one of my arrays as it is an observable array (mobX and react things) – waze Dec 29 '17 at 14:48
I noticed that on array filter, if any value is empty it won't compare the rest, so it won't return anything. Is there anyway to ignore null values? @Nina Scholz – waze Dec 29 '17 at 22:43

score 0 · Answer 2 · answered Dec 29 '17 at 14:02

like this

const a = [
    {
        cod: 123,
        brand: 'Audi',
        model: 'A3',
        price: 15000,
        km: 20000,
    },
    {
        cod: 456,
        brand: 'BMW',
        model: 320,
        price: 20000,
        km: 30000,
    },
];

const b = [
    {
        brand: 'Audi',
        model: 'A3',
        price: 100000,
        km: 100000,
    },
];
function compareTwo(a, b) {
    let obj = {};
    for (let element of a) {
        if (element.model === b[0].model && element.brand === b[0].brand) {
            if (b[0].price <= 100000 && 100000 >= b[0].km)
                obj.model = element.model;
                obj.brand = element.brand;
                if(element.price === 100000) return null ;
               return obj ;
        }
    }
    return null ;
}
let myObj = compareTwo(a,b);
console.log(myObj);

synthet1c · Answer 3 · 2017-12-29T14:26:42.647

Nina did the same answer as me a little faster, so here is an extended version that allows searching with dynamic keys, if it's a number the cars param needs to be less than or equal to the search param.

const cars = [
  {cod: '123', brand: 'Audi', model: 'A3', price: 15000, km: 20000},  // pass
  {cod: '123', brand: 'Audi', model: 'A3', price: 30000, km: 40000},  // pass 
  {cod: '124', brand: 'Audi', model: 'A6', price: 15000, km: 120000}, // pass 2nd query
  {cod: '125', brand: 'Audi', model: 'A8', price: 150000, km: 12000}, // fail price
  {cod: '456', brand: 'BMW', model: '320', price: 20000, km: 30000},  // fail all
]

const searches = [
  {brand: 'Audi', model: 'A3', price: 100000, km: 100000},
  {brand: 'Audi', model: 'A6'}
]

console.log(
  // filter the cars
  cars.filter(car =>
    // iterate over the searches array to check the car to the search params
    searches.some(
      // check the requirements
      search => (
        // loop over each key in the search params object
        Object.keys(search).every(
          key => isNaN(search[key])
            ? car[key] === search[key]
            : car[key] <= search[key]
        )
      )
    )
  )
)

<script src="https://codepen.io/synthet1c/pen/KyQQmL.js"></script>

Compare 2 arrays of objects (with parameters) and return equals

3 Answers3