Setting the value in NSDictionary from JSON response - ios

Question

I have parsed the JSON data, now while setting the JSON to my NSDictionary there might be certain keys in the JSON that might not be present. I want to check if the key is present in the JSON parsed to me and if not, set blank field as value to the key in the `NSDictionary' object.
jsonData = ["id": ((json["idnumber"]) as? String!)!,
"Name": ((json["name"]) as? String!)!,
"Roll Number": ((json["rollnumber"]) as? String!)!,
"Class": ((json["class"]) as? String!)!,
"Marks": ((json["marks"]) as? String!)!,
"Gender": ((json["gender"]) as? String!)!]
So in the above case, the marks field may or may not be present in the JSON. I want to check this and assign respective value to the corresponding key in jsonData.
I tried using "??", but it takes lot of compilation time.

Answer 1

You can use if let or guard for conditional optional wrapping for that like this.
var jsonData = [String : String]
if let num = json["idnumber"]) as? String {
jsonData["id"] = num
}
else {
jsonData["id"] = num
}
and so on for others.
Edit: You can also try like this.
var id = name = rollNum = class = ""
if let num = json["idnumber"]) as? String {
id = num
}
if let sname = json["name"]) as? String {
name = sname
}
...
Then at last create Dictionary
var jsonData = ["id": id, "name": name, ...]

Answer 2

You can set the value if present otherwise blank string (""). This will prevent crash. Try below code:-
let idValue = dictionary["idnumber"] as? String ?? ""
let name = dictionary["name"] as? String ?? ""
let rollNumber = dictionary["rollnumber"] as? String ?? ""
let className = dictionary["class"] as? String ?? ""
let marks = dictionary["marks"] as? String ?? ""
let gender = dictionary["gender"] as? String ?? ""
let jsonDic : NSMutableDictionary = NSMutableDictionary()
jsonDic.setObject(idValue, forKey: "id")
jsonDic.setObject(name, forKey: "name")
jsonDic.setObject(className, forKey: "class")
jsonDic.setObject(rollNumber, forKey: "rollNumber")
jsonDic.setObject(marks, forKey: "marks")
jsonDic.setObject(gender, forKey: "gender")