Use reduce for group array by identifier, JavaScript

Question

Closed. This question needs to be more focused. It is not currently accepting answers. question from:https://stackoverflow.com/questions/65617202/use-reduce-for-group-array-by-identifier-javascript

Answer 1

You can do the following,

var arraJson = [
{
    "name" : "a",
    "department": "a"
},
{
    "name" : "b",
    "department": "a"
},
{
    "name" : "c",
    "department": "b"
}]

res = arraJson.reduce((prev, curr) => {
  let index = prev.findIndex(item => item.department === curr.department);
  if(index > -1) {
    prev[index].employee.push(curr.name);
  } else {
    prev.push({ 'department': curr.department, 'employee': [curr.name] });
  }
  return prev;
}, []);

console.log(res);