Javascript using variable as key to get nested object value

Question

Assume I have the following object:

var jsonObj = {  
  "response":{  
    "result":{  
      "status":{
        "name": "Eric"
      }
    }
  }
}

And now i'd like to dynamically access a nested property:

jsonKey = "response.result.status.name";
console.log("the status is: " + jsonObj.jsonKey);  //I cannot call jsonObj.jsonKey here

Is there any way to achieve this?

@btzr Even if this is my jsonValue? response.result.status.name — tiger_groove
– tiger_groove, Commented Mar 20, 2018 at 2:15
Possible duplicate of Dynamically access object property using variable — btzr
– btzr, Commented Mar 20, 2018 at 2:16

connexo · Accepted Answer · 2018-03-20 14:42:03Z

4

You cannot access a deeply nested property as simple as you expect. Instead you need to use the obj[propertyNameAsString] syntax to dive deeper into the response one by one.

This would be one way of getting there:

let response = {
  "response": {
    "method": "GetStatus",
    "module": "Module",
    "data": null,
    "result": {
      "status": {
        "name": "Eric"
      },
      "id": 1
    },
    "result_code": {
      "error_code": 0
    }
  }
}

let keyString = "response.result.status.name"
let keyArray = keyString.split('.'); // [ "response", "result", "status", "name" ]
var result = response;

for (key of keyArray) {
  result = result[key]
}

console.log(result)

Please be aware that this is not failsafe against cases where one of those strings in keyArray does not exist as a property on the preceding object.

edited Mar 20, 2018 at 14:42

answered Mar 20, 2018 at 3:54

connexo

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3 Comments

tiger_groove Over a year ago

Ah, i see now. This makes much more sense! Thank you !

kritzikratzi Over a year ago

this breaks in some cases (like objects being null). the question posted by @btzr constains an answer with a safer implementation: stackoverflow.com/a/45322101/347508

Code Guru Over a year ago

even object can be like {a : { "my-key": "my-value"}}

Elezar · Accepted Answer · 2023-12-01 03:08:27Z

-1

You can use code like this:

something['bar']

Where bar is your variable that has been converted to string, in our case:

jsonObj[`${jsonKey}`]

edited Dec 1, 2023 at 3:08

Elezar

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answered Feb 7, 2023 at 12:10

Ahamisi God'sFavour

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1 Comment

Elezar Over a year ago

Why are you using string interpolation on the key, rather than just using the key variable directly as jsonObj[jsonKey]?

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