javascript - Manipulate JSON from TypeScript

Question

I have the following JSON data.

[{'connectionId': 1, 'roomId': 140, 'connectionName': 'Hai'},
 {'connectionId': 1, 'roomId': 147, 'connectionName': 'Hai'},
 {'connectionId': 2, 'roomId': 100, 'connectionName': 'hello'},
 {'connectionId': 2, 'roomId': 140, 'connectionName': 'hello'}]

I want to retrieve response like the below from the above data using typescript

  [ { 'connectionId': 1, 'roomId': [ 140, 147] , 'connectionName': 'Hai'} 
  , { 'connectionId': 2, 'roomId': [ 100, 140] , 'connectionName': 'hello'} 
  ] 
   

How to solving this?

Answer 1

this way...

const data = 
      [ { connectionId: 1, roomId: 140, connectionName: 'Hai' } 
      , { connectionId: 1, roomId: 147, connectionName: 'Hai' } 
      , { connectionId: 2, roomId: 100, connectionName: 'hello' } 
      , { connectionId: 2, roomId: 140, connectionName: 'hello' } 
      ] 
  , result = data.reduce((a,{connectionId,roomId,...more})=>
      {
      let p = a.find(x=>x.connectionId===connectionId)
      if(!p)
        {
        p = { connectionId, roomId:[],...more}
        a.push(p)
        }
      p.roomId.push(roomId)
      return a
      },[])
      
console.log( result )

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