How to test if a property exists on a JSON object?

[RTSMikeM]

Xcode 13.4.1 with SwiftUI

Given a simple JSON object (hash)
How can I check if an optional property exists?

Ex: JSON object is of type SwiftyJSON:

if(JSON.exists("myOptionalProperty") {
//DO SOMETHING
}

Either I'm missing this or it's a lacking feature.

[luoxiu]

let string = """
{
  "foo": null
}
"""

let json = JSON(parseJSON: string)

// check if the key exists
json["foo"].exists() // true

// check if the key is null
json["bar"].type == .null // true