Merge nested array of objects by comparing key

Question

• I have an 3 nested array of Objects and I need to merge them all in single array of objects by comparing key. and if any object have same key then their inner object will merge. And if key is not same then also the nested array of objects will merge*

var obj1 = {    
    a: {
    c: 3
  }
}

var obj2 = {    
    b: {
    e: 40
  }
}

var obj3 = {    
    d: {
    x: 30
  },
  a: {
    f: 66
  }
}

// The expected output will be like this - 

// 
/*OUTPUT::: 
{
    a: {
    c: 3,
    f: 66
  },
  b: {
    e: 40
  },
  d: {
    x: 30
  }
}

Please tell me which approach would be suitable ?

Answer 1

You can group the objects using Array.prototype.reduce.

const 
  obj1 = { a: { c: 3 } },
  obj2 = { b: { e: 40 } },
  obj3 = { d: { x: 30 }, a: { f: 66 } };

const res = [obj1, obj2, obj3].reduce((r, o) => {
  Object.entries(o).forEach(([k, v]) => {
    r[k] = { ...r[k], ...v };
  });
  return r;
}, {});

console.log(res);