How to merge array of objects if duplicate values are there, if key is common then merge common values in single key

Question

This is an input array of object

var array= [
    { name : "c", arr: "d" },
    { name : "a", arr: "b" },
    { name : "c", arr: "e" },
    { name : "a", arr: "b" },
    { name : "c", arr: "d" }
];

result should be like

var result =[
     { name : "c", arr: "d,e" },
     { name : "a", arr: "b" }
]

@CertainPerformance look proper to question this differs from as you mentioned — Ajay yadav, Aug 29 '19 at 08:22
if I have no idea how can I post my effort dude @CertainPerformance — Ajay yadav, Aug 29 '19 at 08:26

Jack Bashford · Answer 1 · 2019-08-29T07:50:51.417

Use reduce, a Set to store the unique letters, then join them together with map at the end:

var array= [
    { name : "c", arr: "d" },
    { name : "a", arr: "b" },
    { name : "c", arr: "e" },
    { name : "a", arr: "b" },
    { name : "c", arr: "d" }
];

const res = Object.values(array.reduce((a, { name, arr }) => {
  a[name] = a[name] || { name, arr: new Set() };
  a[name].arr.add(arr);
  return a;
}, {})).map(({ name, arr }) => ({ name, arr: [...arr].join(",")}));

console.log(res);

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How to merge array of objects if duplicate values are there, if key is common then merge common values in single key

1 Answers1