How do you log content of a JSON object in Node.js?

Question

Is it possible to print an objects contents e.g. methods and attributes in Node.js?

At the moment I'm trying to print the session object and get the following:

console.log("Session:" + session);
> Session:[object Object]

Maybe in a similar way to print_r(array) in PHP, or using .toString in Java.

For a more intuitive and visual output of objects take a look at nodedump: https://github.com/ragamufin/nodedump — ragamufin, Oct 03 '13 at 23:41

score 301 · Accepted Answer · edited Jul 16 '17 at 10:26

301

Try this one:

console.log("Session: %j", session);

If the object could be converted into JSON, that will work.

edited Jul 16 '17 at 10:26

Peter Mortensen

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answered Sep 15 '11 at 08:59

Alexander Sulfrian

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I am trying to do this for the request object but it shows error TypeError: Converting circular structure to JSON Is there any way to limit the depth – Neil May 17 '13 at 10:29
anyway to pretty print this? – chovy Aug 13 '13 at 06:24
6

@chovy: something like this might work: console.log(JSON.stringify(json, null, 4)); – Eric Brandel Sep 03 '13 at 21:05
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this worked for me: `console.log("Session: %O", session);` https://developer.mozilla.org/en-US/docs/Web/API/console#Outputting_text_to_the_console – JP Lew Jun 12 '19 at 22:02
Worked for my json API response! Thanks – rodrigorf Oct 19 '19 at 19:58

score 149 · Answer 2 · edited Sep 17 '14 at 07:58

149

function prettyJSON(obj) {
    console.log(JSON.stringify(obj, null, 2));
}

// obj -> value to convert to a JSON string
// null -> (do nothing)
// 2 -> 2 spaces per indent level

JSON.stringify on MDN

edited Sep 17 '14 at 07:58

Jake Berger

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answered Jun 27 '12 at 19:46

ccgillett

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by far the best answer +1! – buycanna.io Dec 27 '18 at 23:16

score 33 · Answer 3 · answered Apr 13 '12 at 09:51

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To have an output more similar to the raw console.log(obj) I usually do use console.log('Status: ' + util.inspect(obj)) (JSON is slightly different).

answered Apr 13 '12 at 09:51

lapo

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This gives "util is not defined". You must `var util = require("util") first. Also, the sub-objects still turn out as [Object] and not the JSON string that represents them. – juanpaco May 01 '13 at 12:26
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To remove the depth limit, use: `require('util').inspect(obj, {depth:null})` – lapo May 02 '13 at 10:57

Marwen Trabelsi · Answer 4 · 2015-06-23T05:50:06.233

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This will work with any object:

    var util = require("util");
    console.log(util.inspect(myObject, {showHidden: false, depth: null}));

edited Jun 23 '15 at 05:50

answered Aug 04 '14 at 05:45

Marwen Trabelsi

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This works great for error objects. None of their properties show up in the other solutions. – Chris Jun 22 '15 at 21:14
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This just hangs for me. I think circular references in an object crashes it – Richard May 19 '16 at 15:25
@Richard it probably hang(ed) for you due to the depth option being set to `null`. Inspect has built-in treatment for circular references. – kbtz Aug 15 '17 at 21:16

score 7 · Answer 5 · answered Dec 17 '13 at 02:56

7

console.dir() is the most direct way.

answered Dec 17 '13 at 02:56

rainabba

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console.dir(someJsonObject); still leaves nested objects unprinted, for me. – nyarasha Nov 10 '15 at 17:28
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I think it won't drill into objects through their prototype and it won't deal with certain recursion. You're either going to have to do something like console.log(JSON.stringify()) or something more specific to your object if .dir() isn't sufficient. If you have more info about the object, perhaps more specific advice can be given. – rainabba Nov 11 '15 at 20:43
It can take the same options as util.inspect. Add {depth:null} – nikc.org Feb 26 '17 at 09:50

score 0 · Answer 6 · answered May 16 '18 at 13:14

0

console.log(obj);

Run: node app.js > output.txt

answered May 16 '18 at 13:14

Rostyslav Bornitskyi

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score 0 · Answer 7 · answered Nov 06 '18 at 11:08

0

This will for most of the objects for outputting in nodejs console

var util = require('util')
function print (data){
  console.log(util.inspect(data,true,12,true))
  
}

print({name : "Your name" ,age : "Your age"})

answered Nov 06 '18 at 11:08

manoj kumar

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score 0 · Answer 8 · answered May 25 '22 at 16:12

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console.dir with the depth argument set will do the trick. This will print JSON objects to any arbitrary depth. Depth:null means print every level.

console.dir(someObject, { depth: null })

answered May 25 '22 at 16:12

john ktejik

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How do you log content of a JSON object in Node.js?

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