value keys is not a member of play.api.libs.json.JsValue - json

Question

I'm try to get the head from the keys of JsValue type in Scala. I googled a lot to know how to get the head key from JsValue type.
Finally, I found that result.keys.head is the way to get the head key, but it throws error value keys is not a member of play.api.libs.json.JsValue.
And my result variable has the below form of data:
{
"intents": [{
"intent": "feeling",
"confidence": 0.1018563217175903
}],
"entities": [],
"input": {
"text": "{reset-encounter}"
},
"output": "Good"
}
Code:
import play.api.libs.json._
val jsonStr = """
{
"intents": [{
"intent": "feeling",
"confidence": 0.1018563217175903
}],
"entities": [],
"input": {
"text": "{reset-encounter}"
},
"output": "Good"
}
"""
val result = Json.parse(jsonStr)
println("key: ", result.keys.head)
At result.keys.head line, throws error.
I'm not sure but I think, may be I'm doing something wrong here.

Answer 1

Json.parse produces a JsValue, which could represent any type of json object (boolean, number, array, etc). If you know you're working with an object, you can use .as[JsObject]:
import play.api.libs.json._
val result = Json.parse(jsonStr).as[JsObject]
println("key: " + result.keys.head)

Answer 2

What are you trying to get? That's not the way to deal with play.api.Json objects.
.keys would result in a Map, not in a JsValue.
Check the documentation: https://www.playframework.com/documentation/2.5.x/ScalaJson
If you want to access a specific key (https://www.playframework.com/documentation/2.5.x/ScalaJson#Traversing-a-JsValue-structure) you should try:
result \ "keyName"
or for a recursive search:
result \\ "keyName"