Lodash Multidimensional Pluck

With the lodash library, I'd like to be able to pluck multiple values into a multi-dimensional array, along the lines of: var arr = [{ a: 2, b: 3, c: 4 }, { a: 1, b: 4, c: 2 }]; _.

Solution 1:

There is no pluck on multiple keys, but you can do this:

_.map(['a', 'c'], function(path) {
  return _.pluck(arr, path);
});

This will return values grouped by key.

Edit:

_.mpluck = function(collection, paths) {
  return _.zip(
    _.map(paths, function(path) {
      return _.pluck(collection, path);
    })
  );
}

var arr = [{ a: 2, b: 3, c: 4 }, { a: 1, b: 4, c: 2 }];

_.mpluck(arr, ['a', 'c']) --> [[2, 4], [1, 2]]

this will replace each object by an array of the specified keys.

---

Without lodash:

functionmpluck(collection, paths) {
  return collection.map(function(obj) {
    return paths.map(function(path) {
      return obj[path];
    });
  });
}

Solution 2:

Solution without lodash:

functionpluck(arr, k) {
    return arr.reduce(function (r, a) {
        r.push(k.reduce(function (rr, aa) {
            rr.push(a[aa]);
            return rr;
        }, []));
        return r;
    }, []);
}

var arr = [{ a: 2, b: 3, c: 4 }, { a: 1, b: 4, c: 2 }],
    x = pluck(arr, ['a', 'c']);

document.write('<pre>' + JSON.stringify(x, 0, 4) + '</pre>');