javascript - Filter object properties by key in ES6

Question

Let's say I have an object:

{
  item1: { key: 'sdfd', value:'sdfd' },
  item2: { key: 'sdfd', value:'sdfd' },
  item3: { key: 'sdfd', value:'sdfd' }
}

I want to create another object by filtering the object above so I have something like.

 {
    item1: { key: 'sdfd', value:'sdfd' },
    item3: { key: 'sdfd', value:'sdfd' }
 }

I am looking for a clean way to accomplish this using Es6, so spread operators are available to me.

Answer 1

If you have a list of allowed values, you can easily retain them in an object using:

const raw = {
  item1: { key: 'sdfd', value:'sdfd' },
  item2: { key: 'sdfd', value:'sdfd' },
  item3: { key: 'sdfd', value:'sdfd' }
};

const allowed = ['item1', 'item3'];

const filtered = Object.keys(raw)
  .filter(key => allowed.includes(key))
  .reduce((obj, key) => {
    obj[key] = raw[key];
    return obj;
  }, {});

console.log(filtered);