Example 1: javascript group by property array of objects
function groupArrayOfObjects(list, key) {
return list.reduce(function(rv, x) {
(rv[x[key]] = rv[x[key]] || []).push(x);
return rv;
}, {});
};
var people = [
{sex:"Male", name:"Jeff"},
{sex:"Female", name:"Megan"},
{sex:"Male", name:"Taylor"},
{sex:"Female", name:"Madison"}
];
var groupedPeople=groupArrayOfObjects(people,"sex");
console.log(groupedPeople.Male);
console.log(groupedPeople.Female);
Example 2: javascript group by key
var cars = [{ make: 'audi', model: 'r8', year: '2012' }, { make: 'audi', model: 'rs5', year: '2013' }, { make: 'ford', model: 'mustang', year: '2012' }, { make: 'ford', model: 'fusion', year: '2015' }, { make: 'kia', model: 'optima', year: '2012' }],
result = cars.reduce(function (r, a) {
r[a.make] = r[a.make] || [];
r[a.make].push(a);
return r;
}, Object.create(null));
console.log(result);
Example 3: javascript group by key
result = array.reduce((h, obj) => Object.assign(h, { [obj.key]:( h[obj.key] || [] ).concat(obj) }), {})
Example 4: js group objects in array
let group = cars.reduce((r, a) => { console.log("a", a); console.log('r', r); r[a.make] = [...r[a.make] || [], a]; return r;}, {});console.log("group", group);