One-liner to take some properties from object in ES 6

Here's something slimmer, although it doesn't avoid repeating the list of fields. It uses "parameter destructuring" to avoid the need for the v parameter.

({id, title}) => ({id, title})

(See a runnable example in this other answer).

@EthanBrown's solution is more general. Here is a more idiomatic version of it which uses Object.assign, and computed properties (the [p] part):

function pick(o, ...props) {
    return Object.assign({}, ...props.map(prop => ({[prop]: o[prop]})));
}

If we want to preserve the properties' attributes, such as configurable and getters and setters, while also omitting non-enumerable properties, then:

function pick(o, ...props) {
    var has = p => o.propertyIsEnumerable(p),
        get = p => Object.getOwnPropertyDescriptor(o, p);

    return Object.defineProperties({},
        Object.assign({}, ...props
            .filter(prop => has(prop))
            .map(prop => ({prop: get(props)})))
    );
}

I don't think there's any way to make it much more compact than your answer (or torazburo's), but essentially what you're trying to do is emulate Underscore's pick operation. It would be easy enough to re-implement that in ES6:

function pick(o, ...fields) {
    return fields.reduce((a, x) => {
        if(o.hasOwnProperty(x)) a[x] = o[x];
        return a;
    }, {});
}

Then you have a handy re-usable function:

var stuff = { name: 'Thing', color: 'blue', age: 17 };
var picked = pick(stuff, 'name', 'age');

The trick to solving this as a one-liner is to flip the approach taken: Instead of starting from original object orig, one can start from the keys they want to extract.

Using Array#reduce one can then store each needed key on the empty object which is passed in as the initialValue for said function.

Like so:

const orig = {
  id: 123456789,
  name: 'test',
  description: '…',
  url: 'https://…',
};

const filtered = ['id', 'name'].reduce((result, key) => { result[key] = orig[key]; return result; }, {});

console.log(filtered); // Object {id: 123456789, name: "test"}

alternatively...

const filtered = ['id', 'name'].reduce((result, key) => ({
    ...result, 
    [key]: orig[key] 
}), {});

console.log(filtered); // Object {id: 123456789, name: "test"}

A tiny bit shorter solution using the comma operator:

const pick = (O, ...K) => K.reduce((o, k) => (o[k]=O[k], o), {})

console.log(
  pick({ name: 'John', age: 29, height: 198 }, 'name', 'age')
)

One-liner to take some properties from object in ES 6

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