Prettier debug output printing Swift Dictionary in Xcode

Question

When I use print() on a dictionary in Swift, it comes out nice and pretty in the console, with a key and a value.

object = Optional({
customerId = 1         


        

Answer 1

⚠️ The (previously) accepted answer only provided the dictionary as a non-formatted single line string like so:

Optional(["transactionId": 333, "customerId": 111, "extraId": 444])

➡️ As soon as you get more keys and embedded objects/dictionaries it becomes difficult to read.

---

PrettyPrint JSON solution

• To get a nice json formatting (indentations, newlines, etc) you can define an alias (I named mine pjson) by running this command in your lldb terminal (source):

command regex pjson 's/(.+)/expr print(NSString(string: String(data: try! JSONSerialization.data(withJSONObject: %1, options: .prettyPrinted), encoding: .utf8)!))/'

• You probably don't want to re-define the alias everytime you open XCode, so run the following command to append the alias definition to ~/.lldbinit:

echo "command regex pjson 's/(.+)/expr print(NSString(string: String(data: try! JSONSerialization.data(withJSONObject: %1, options: .prettyPrinted), encoding: .utf8)!))/'" >> ~/.lldbinit

• This will create the pjson alias which you can use in your lldb terminal in XCode:

pjson object

---

Comparing the outputs for the following Swift object:

let object: Any? = [
    "customerId": 111,
    "transactionId": 333,
    "extraId": 444,
    "embeddedDict": [
        "foo": true
    ]
]

❌ Output of po print(data)

Optional(["transactionId": 333, "embeddedDict": ["foo": true], "customerId": 111, "extraId": 444])

✅ Output of pjson

{
  "transactionId" : 333,
  "embeddedDict" : {
    "foo" : true
  },
  "customerId" : 111,
  "extraId" : 444
}