How To Compare And Push Field To Sub Array In Object

I have an object which contain name and id. Second object has some fields and that id field from first object. For Example: FirstObj = [{ _id: '48765465f42424', Name : 'Sample

Solution 1:

Try this

secondObj.subarray.forEach(function(item){
if(item.FirstObjid==FirstObj._id)
    item.Name = FirstObj.Name
})

Solution 2:

Use map function and compare the object ids like this

var secondObj =  [{
  Field1 : 5464,
  subarray : [{
        Field2 : 14654,
        Field3 : 'sfsadf',
        FirstObjid : '48765465f42424'
        }]
    },
    {
  Field1 : 2145,
  subarray : [{
        Field2 : 544644,
        Field3 : 'awrfsa',
        FirstObjid : '48765465f654654'
        }]
    }]
    
 varFirstObj = [{
  _id: '48765465f42424',
  Name : 'Sample'
},{
  _id: '48765465f654654',
  Name : 'Sample1'
}]

secondObj.subarray = secondObj.map(o => o.subarray.map(k=>FirstObj.map(l=> { 
  if(l._id == k.FirstObjid){
     k.Name = l.Name
  }
  return o;
})))
 

console.log(secondObj)