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 = 111;
transactionId = 333;
extraId = 444;
})

When I run po on that same dictionary, it spits out this nonsense dump which is incredibly hard to read.

▿ Optional<Any>
▿ some : 3 elements
▿ 0 : 2 elements
  ▿ .0 : transactionId
  - .1 : 333
▿ 1 : 2 elements
  ▿ .0 : customerId
  - .1 : 111
▿ 2 : 2 elements
  ▿ .0 : extraId
  - .1 : 444

Using just p is even worse

(Any?) $R8 = some {
  payload_data_0 = 0x0000000170e679c0 {
  Swift._SwiftNativeNSDictionary = {}
  _heapBufferBridged_DoNotUse = 0x0000000170e679d0 {}
  nativeStorage = {
    buffer = 0x00000001703e4300 {
      Swift.ManagedBuffer = {}
    }
    initializedEntries = (values = 0x00000001703e4328, bitCount = 4)
    keys = 0x00000001703e4330
    values = 0x00000001703e4390
    }
  }
  payload_data_1 = 0x0000000000000000
  payload_data_2 = 0x0000000000000000
  instance_type = 0x0000000105ffc3f8
}

What can I do in the console to see my variables in a way that I can actually read them without having to sift through all this nonsense?

PS - In this case I am printing an Optional<Any> object that happens to be a dictionary, but it's the same with a non-optional Dictionary.

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
}