You can do it like this in both Underscore and Lodash (3.x and 4.x).
var data = [{
"name": "jim",
"color": "blue",
"age": "22"
}, {
"name": "Sam",
"color": "blue",
"age": "33"
}, {
"name": "eddie",
"color": "green",
"age": "77"
}];
console.log(
_.chain(data)
// Group the elements of Array based on `color` property
.groupBy("color")
// `key` is group's name (color), `value` is the array of objects
.map((value, key) => ({ color: key, users: value }))
.value()
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>
Original Answer
var result = _.chain(data)
.groupBy("color")
.pairs()
.map(function(currentItem) {
return _.object(_.zip(["color", "users"], currentItem));
})
.value();
console.log(result);
Note: Lodash 4.0 onwards, the .pairs
function has been renamed to _.toPairs()