const workers = [
{ name: 'R2D2', lang: 'cpp' },
{ name: 'Emma', lang: 'c' },
{ name: 'Arthur', lang: 'cpp' },
];
const groupeditems = workers.reduce((acc, person) => {
(acc[person.lang] = acc[person.lang] || []).push(person);
return acc;
}, {});
console.log(groupeditems);
/*
run:
{
cpp: [ { name: 'R2D2', lang: 'cpp' }, { name: 'Arthur', lang: 'cpp' } ],
c: [ { name: 'Emma', lang: 'c' } ]
}
*/