Check if a key exists in play.api.libs.json.Json

Question

contains like functionality for play.api.libs.json.Json

val data=Map("id" -> "240190", "password" -> "password","email" -> "[email protected]")

data.contains("email")//true


val info=Json.obj("id" -> "240190", "password" -> "password","email" -> "[email protected]")

now how to check info contains email or not?

Emeldaemelen

Answer 1

info.keys.contains("email")

The .keys gives you back a Set with the key values and then you can call the contains method, I'm not sure there's a more direct way to do it.

Jonell

keys yields a Set. – Palliative

Thanks, It was a typo. – Jonell

Answer 2

(info \ "email").asOpt[String].isEmpty

as asOpt would return Optional, we can have isEmpty simple check, this would do what we want.

Loree

Some explanation might help future visitors. – Demos

@errhunter thankq! as asOpt would return Optional, we can have isEmpty simple check, this would do what we want. – Loree

You can edit your answer to add the explanation, instead of writing it as a comment. – Kaleb

Answer 3

(info \ "email").asOpt[String] match {
  case Some(data) => println("here is the value for the key email represented by variable data" + data)
  case None => println("email key is not found") 
}

Melchizedek

This won't work when you do things like .asOpt[Boolean], which will always give you a Some(false) when the key doesn't exist. – Angelitaangell

Answer 4

(info \ "email").asOpt[String] works only if email is a string. If email is an object, (info \ "email").asOpt[String] will be None. An alternative is to match (info \ "email").toOption to Some or None.

Stapleton