Dynamically Change object value according to an Array of keyname in Javascript

Question

So I want to change the content of object "alfa" according to a list of keyNames according to the newValue.

let alfa = { 
    bravo : { 
        charlie : { 
            delta : "echo" 
        } 
    } 
}

const newValue = { foxtrot : "golf" }

I want to do something like this, dynamically:

alfa[keyNames] = newValue

// where if

const keyNames = ["bravo", "charlie"]
// would do:
alfa["bravo"]["charlie"] = newValue

// or if 

const keyNames = ["bravo"]
// would do:
alfa["bravo"] = newValue

How to do that?

I know I can do this, but there is probably a way to cover every possibles cases...

if(keyNames.length === 1){ alfa[keyNames[0]] = newValue }
if(keyNames.length === 2){ alfa[keyNames[0]][keyNames[1]] = newValue }
...

Can you please elaborate more on what you mean by dynamically. — Harry Bomrah, Jul 02 '20 at 04:10

score 1 · Accepted Answer · answered Jul 02 '20 at 04:36

it would be a setValue function.

const alfa = {};
const keyNames = ["bravo", "charlie"];

function setValue(target,keyPath,value){
  [target,...keyNames].reduce((object,keyName) => {
    if( keyName === keyPath[keyPath.length-1] ){
      object[keyName] = value;
    }

    object[keyName] = object[keyName] || {};
      return object[keyName]
    })
}

setValue(alfa,keyNames,"oboo")

Dynamically Change object value according to an Array of keyname in Javascript

1 Answers1