如何从具有不同值的两个对象返回键和值

Question

How would I loop over two objects and only return a list of the keys & values that were different?

let list = [];

let previousObject = {
    key: 'key_1',
    name: 'Previous name',
    age: '30',
    location: '12345 Main St.',
    height: '77',
    weight: '215',
    ...
}

let newObject = {
    key: 'key_1',
    name: 'New name',
    age: '25',
    location: '54321 Main St.',
    height: '77',
    weight: '195',
    ...
}

I would like the list to return...

list = [{ name: 'New name', age: '25', location: '54321 Main St.' }]

Things to consider:

• The previousObject might contain more keys than the newObject
• Checking for these differences might happen more than once per user session

Answer 1

In your example list is an array with only one object containing all the differences. To get that object, you can do this:

 let list = []; let previousObject = { key: 'key_1', name: 'Previous name', age: '30', location: '12345 Main St.', height: '77', weight: '215', } let newObject = { key: 'key_1', name: 'New name', age: '25', location: '54321 Main St.', height: '77', weight: '195', } let diff = {} for (const key in newObject) { if (previousObject[key].= newObject[key]) { diff[key] = newObject[key] } } console.log(diff)