Swift 4 parse string to json object - ios

Question

I have implement qr code scanner, Where in "metadataOutput" delegate method I have received response which has key like "stringValue", Value of this key is
stringValue "'{ "part_number":"154100102232",
"lot_number":"03S32401701344"}'"
I want parse string value to json object, but I am not able to do that.
let data = stringValue.data(using: .utf8)!
do {
if let json = try JSONSerialization.jsonObject(with: data, options : .allowFragments) as? [AnyHashable:Any]
{
print("Json:::",json)
// post a notification
// NotificationCenter.default.post(name: NSNotification.Name(rawValue: "SCANNER_DATA"), object: nil, userInfo: json)
} else {
print("bad json")
}
} catch let error as NSError {
print(error)
}
I have followed above approach to parse string to json, but I have found following error.
Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around
character 0." UserInfo={NSDebugDescription=Invalid value around
character 0.}
Can anyone have any idea about this?

Answer 1

Better have an extension to String like this
extension String{
func toDictionary() -> NSDictionary {
let blankDict : NSDictionary = [:]
if let data = self.data(using: .utf8) {
do {
return try JSONSerialization.jsonObject(with: data, options: []) as! NSDictionary
} catch {
print(error.localizedDescription)
}
}
return blankDict
}
}
Use like this
let dict = stringValue.toDcitionary()
Or you can use pod for all these kind of work from UtilityKit on github https://github.com/utills/UtilityKit

Answer 2

This works with me , You string has ' character around trailing "' content '"
let stringValue = """
{"part_number":"154100102232","lot_number":"03S32401701344"}
"""
let data = stringValue.data(using: .utf8)!
do {
if let json = try JSONSerialization.jsonObject(with: data) as? [String:Any]
{
print("ewtyewytyetwytewytewtewytew",json)
} else {
print("ewtyewytyetwytewytewtewytew","bad json")
}
} catch let error as NSError {
print("ewtyewytyetwytewytewtewytew",error)
}