Print JSON with "pretty" (indented) format

Question

If I create a JSON object and print it on the console:

LJSONObject:= TJSONObject.Create;
LJSONObject.AddPair(TJSONPair.Create(TJSONString.Create('Hello'), TJSONString.Create('World')));
LJSONObject.AddPair(TJSONPair.Create(TJSONString.Create('Ciao'), TJSONString.Create('Mondo')));
Writeln(LJSONObject.ToString);

the result is:

{"Hello":"World", "Ciao":"Mondo"}

How I can print the result with nicer indentation, like this?

{
   "Hello":"World",
   "Ciao":"MOndo"
}

There's no support of `TJSONObject` for pretty print at this time. But with `PrettyPrintJSON` function from [`this question`](http://stackoverflow.com/q/11797583/960757) you can write something [`like this`](http://pastebin.com/QgkYffN3). — TLama, Jul 10 '14 at 10:07
It's not "correct" indentation - indentation doesn't matter for a JSON parser. It's useful for humans reading it though. That makes it "pretty printing" as @David Heffernan calls it in his answer below, or something similar. — David, Jul 10 '14 at 10:07
You can also use online tools like http://jsonprettyprint.net if you don't mind copying pasting. — Javaaaa, Nov 19 '14 at 17:04

score 5 · Accepted Answer · edited May 23 '17 at 11:45

5

TJSONObject does not support pretty printing.

Other JSON libraries do. For instance SuperObject, as discussed here: How do I pretty-print JSON in Delphi?

edited May 23 '17 at 11:45

Community

1
1

answered Jul 10 '14 at 09:59

David Heffernan

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4

Since Delphi XE5 there is a formatter [`REST.Json.TJson.Format`](http://docwiki.embarcadero.com/Libraries/XE5/en/REST.Json.TJson.Format) – Sir Rufo Aug 26 '15 at 12:38
That's very helpful, and was very hidden AFAIC. Thanks! – Robbie Matthews Aug 17 '18 at 01:29

score 2 · Answer 2 · answered Aug 17 '18 at 01:37

As Sir Rufo pointed out, there is an inbuilt option as of XE5.

uses REST.JSON,System.JSON;
...
function PrettyJSON(jsonstring:String):String;
    var jdoc:TJSONObject;
begin
    jdoc:=TJSONObject.ParseJSONValue(jsonstring) as TJSONObject;
    result:=TJSON.Format(jdoc)
end;

Print JSON with "pretty" (indented) format

2 Answers2