Check if two arrays of objects have differences isolating the latter

July 20, 2022

I have two arrays of objects. Each object will have a unique property id which, for context, is a filterID retrieved from a dynamoDb database. What I want to achieve is, retrieving an array of the objects that are different given the same id.

const x = [
    {
        1234: "food"
    },
    {
        5678: "animal"
    },
    {
        4444: "car"
    }
]

const y = [
    {
        1234: "food"
    },
    {
        5678: "bread"
    },
    {
        4444: "car"
    }
]

const p = () => x.filter(object1 => {
    return !y.some(object2 => {
        return object1 === object2
    })
})
 console.log(p())

In this scenario I would be looking for something like

const different = [
    {
        5678: "animal"
    },
]

I have tried a few things like on the example above but so far no success.

>Solution :

You’re close, you just need to get the object key and compare the values, instead of comparing the object references.

const p = () => x.filter(object1 => {
    return !y.some(object2 => {
        const key = Object.keys(object1)[0];
        return object1[key] == object2[key];
    })
})
 console.log(p())