Print some JSON

Question

This challenge is straightforward, but hopefully, there are plenty of avenues you can approach it:

You need to print/return a valid JSON object of at least 15 characters, not counting unessential whitespace. Your program should work without any input.

In the interest of clarity, a JSON object starts and ends with curly braces {}, and contains zero or more key:value pairs separated by commas. The full JSON specification can be found at json.org, and the output of your code must pass this validator.

Therefore, any of the following would not be valid:

4                               //Too short, not an object
"really, really long string"    //A string, not an object
["an","array","of","values"]    //An array is not a JSON object
{"this":4      }                //You can't count unessential whitespace
{"1":1,"2":3}                   //Too short
{"a really long string"}        //Not valid JSON, it needs a value
{'single-quoted':3}             //JSON requires double-quotes for strings

However, the following would be valid:

{"1":1,"2":2,"3":3,"4":4}       //Long enough
{"whitespace      ":4}          //This whitespace isn't unessential

Non-programming languages are allowed on this challenge. You may return a string from a function, or print it out. This is a code-golf, so answer it with as little code as possible!

Answer 1

Element, 18 bytes

\{\"a\"\:`9 9^`\}`

Try it online! Outputs {"a":387420489}

This is only three bytes shorter than the naive solution. The first half of the output is hard-coded (too many escape characters to make any other approach feasible), while the value is calculated as 9^9 to make a number long enough.

Answer 2

Jelly, 13 12 bytes

“{"":}”s2jȷ4

TryItOnline!

How?

“{"":}”s2jȷ4 - Main link: no arguments
“{"":}”      - literal ['{','"','"',':','}']
       s2    - split into twos -> [['{','"'],['"',':'],['}']]
         j   - join with
          ȷ4 - literal 10000 -> ['{','"',10000,'"',':',10000,'}']
             - implicit print -> {"10000":10000}

---

previous (13):

“"11”m0“{:}”j

Answer 3

Cheddar, 17 14 bytes

Saved 3 bytes thanks to @ConorO'Brien

->'{":1234}'*2

An anonymous function that returns {":1234}{":1234}, which is a valid JSON object:

{
  ":1234}{": 1234
}

Try it online!

Answer 4

Charcoal, 7 bytes

{"⁹":9}

Try it online!

Runs of printable ASCII characters in Charcoal form literal strings, and expressions lacking any explicit command are printed. So {" and ":9} are just output verbatim. ⁹, however, is an integer literal, and when you print an integer, you get an ASCII-art line that many characters long. The character used for horizonal lines is the hyphen, so the result is:

{"---------":9}

Conveniently, this is exactly 15 characters.

Answer 5

x86-64 machine code, 16 bytes

B8 7B 22 3A 20 AB AB AB AB C7 07 30 7D 7D 00 C3

Try it online!

Produces {": {": {": {": 0}}.

Following the standard calling convention for Unix-like systems (from the System V AMD64 ABI), this takes in RDI a memory address at which to place the result, as a null-terminated byte string.

In assembly:

f:  mov eax, '{' | '"'<<8 | ':'<<16 | ' '<<24
            # Put this value in EAX.
    stosd   # Write it to the output string, advancing the pointer.
    stosd   # Again.
    stosd   # Again.
    stosd   # Again.
    mov DWORD PTR [rdi], '0' | '}'<<8 | '}'<<16 | 0<<24
            # Add this value to the output string.
    ret     # Return.

Answer 6

IBM/Lotus Notes @Formula, 24 23 bytes

Computed value in a Notes field.

"{\"\":"+@Text(@Pi)+"}"

Outputs:

{"":3.14159265358979}

Nothing clever - just uses the shortest possible function that outputs a number then converts it to text for display.

Answer 7

Japt, 11 bytes

There are a multitude of 11-byte programs:

`\{"{O}":1}  // {"[object Object]":1}
`\{"{M}":1}  // {"[object Math]":1}
`\{"{@}":1}  // {"function (X,Y,Z){return }":1}
`\{"{_}":1}  // {"function (Z){return Z}":1}
`\{"{Ð}":1}  // {"Tue Oct 25 2016 12:15:24 GMT-0400 (Eastern Standard Time)":1}
`\{"":{+Ð}}  // {"":1477412000095}

The last two use the Date object; thus, they are non-constant, but always output more than 15 bytes. Explanation:

`\{"   ":1}` // Take this string, 
    {O}      // inserting variable O here.
             // O is an Object, which stringifies to "[object Object]".
             // Implicitly output.

Test it online!

More interesting 12-byte version:

`\{":{L²}}`²

Prints {":10000}{":10000}. Explanation:

`\{":    }`   // Take this string, 
     {L²}     // inserting 100 squared (10000) here,
              // (this yields {":10000})
           ²  // and double.
              // Implicitly output.

Test it online!

Answer 8

Common Lisp, 24 bytes

(format t"{~S:~f}""p"pi)

Prints the following to standard output (23 characters long):

{"p":3.141592653589793}

This is a simple string format which uses the predefined constant PI.

Answer 9

q, 14 bytes

Prints memory usage information about the current process

[email protected] .Q.w`;

Sample output:

q)[email protected] .Q.w`;
{"used":127392,"heap":67108864,"peak":67108864,"wmax":0,"mmap":0,"mphy":16735457280,"syms":585,"symw":18925}

Answer 10

CoffeeScript, 18 16 bytes

Saved 2 bytes thanks to @Caffeinated.tech

->'{"":'+1/3+'}'

Outputs {"":0.3333333333333333}. Sadly, because of the required double-quotes, string interpolation is a byte longer:

->"{\"\":#{1/3}}"

Answer 11

Actionscript 3, 27 bytes

trace(JSON.stringify(int));

outputs

{"MAX_VALUE":2147483647,"length":1,"MIN_VALUE":-2147483648,"prototype":{}}

Answer 12

TSQL(2016 only), 50 BYTES

SELECT*FROM(VALUES(GETDATE()))AS A(a)FOR JSON PATH

Answer 13

PowerShell, 17 bytes

Slightly unclear on how strict the 'no input' thing is, if it's just no user input or of system input is also disallowed. While my best answer isn't shorter than the other PowerShell answer I think it is novel.

ps|ConvertTo-Json

Gets running processes (default return is an object) and converts that object to a json. Several other two and three letter aliases commands work.

Sample output omitted because it's 34115 lines long and trying to redact my username and computername was a pain.

gl|ConvertTo-Json

Gets your current filesystem location (as an object) and converts that object to a json

gci|ConvertTo-Json

Gets the files in your current path (as an object) and converts that object to a json

You can also take things like inherent type definitions (which are part of the language itself) and pipe them into the conversion function.

[xml]|ConvertTo-Json

Gets the definition of the xml datatype and converts that object to a json

[int]|ConvertTo-Json

Gets the definition of the 32bit integer datatype and converts that object to a json

Answer 14

Java 8 (Full Program), 125 Bytes 123 Bytes 116 Bytes

Yes, I know there are shorter ways in Java, as posted above. I just wanted to approach it from a looping perspective.

Thanks to ais523 for saving 2 bytes.
Thanks to Manatwork for saving 7 bytes.

interface C{static void main(String[]a){for(int i=0;i++<9;)System.out.print(i<2?"{":"\""+i+"\":"+i+(i>8?"}":","));}}

Ungolfed

interface C{
    static void main(String[]a){
        //Loop from 0-8, add one to i at start of loop instead of end though
        for(int i=0;i++<9;)
            //If it is a start case simply print { otherwise print "i":i
            //If it is an end case also print } otherwise also print :
            System.out.print(i<2?"{":'"'+i+"\":"+i+(i>8?"}":","));
        }
}

Answer 15

Vim, 13 keystrokes

a{"<esc>9aa<esc>a":0}

Outputs

{"aaaaaaaaa":0}

Answer 16

K (ngn/k), 12 bytes

`0:`j@`a!1e9

Try it online!

Answer 17

Go, 47 bytes

import."fmt"
func f(){Print(`{"X":10,"Y":20}`)}

Attempt This Online!

To STDERR, 32 bytes

func(){print(`{"X":10,"Y":20}`)}

Attempt This Online!

Answer 18

jq -n, 12 bytes

""|match("")

Try it online!

env does not always satisfy the requirement. It depends on the environment, which could even be empty, outputting {}. This solution yields the same result every time:

{
  "offset": 0,
  "length": 0,
  "string": "",
  "captures": []
}

Answer 19

Turtlèd, 15 bytes

'{r'"10:'"r":3}

Try it online

outputs {" ":3}

Explanation

'{               write {
  r              move right, off {
   '"            write "
     10          put 10 in register
       :         move right that many characters (puts spaces in)
        '"r       write ", move right of that character
           ":3}   write :3}

Answer 20

Groovy, 43 Bytes

{groovy.json.JsonOutput.toJson([i:1..9]​)​}

It gives the range 1-9 in JSON stored for i:

{"i":[1,2,3,4,5,6,7,8,9]}

Groovy on Grails, 31 Bytes

def v(){render(params as JSON)}

Controller method, renders the parameters which always include action, controller and a few other meta parameters which results in:

{"action":"v","format":null,"controller":"<Controller Name>"}

When you visit the URL:

http://localhost:8080/<Controller Name>/v

Answer 21

Myth, 28 26 bytes

{"a":"{\":3141}","_":"aa"}

Saved 2 bytes by adapting the solution given by the /// answer.

Myth is a language similar to Thue, contained in a valid JSON object. How appropriate! Here, _ is the initial state, and replaces a with "****". Output:

{":3141}{":3141}

For clarity, I added some spaces:

{
  ":3141}{"  :  3141
}

Previous solutions

28 bytes: {"a":"\"****\"","_":"{a:a}"}. Outputs: {"****":"****"}

Running

I found the interpreter here:

function(m,y,t,h){m=JSON.parse(m);for(y=m._;h=1;){for(t in m)if(t!="_"&&~y.indexOf(t)){y=y.replace(t,m[t]);h=0;break}if(h)break}return y}

Test it out right here:

function myth(m,y,t,h){m=JSON.parse(m);for(y=m._;h=1;){for(t in m)if(t!="_"&&~y.indexOf(t)){y=y.replace(t,m[t]);h=0;break}if(h)break}return y}
b.onclick=function(){o.innerHTML="";o.appendChild(document.createTextNode(myth(q.value)));}

textarea {
  width: 90%;
}
*{font-family:Consolas,monospace;}

<textarea id=q>{"a":"\"****\"","_":"{a:a}"}</textarea>
<br>
<button id=b>execute myth code</button>
<br>
<textarea id=o disabled>output</textarea>

Answer 22

Addict, 200 167 bytes

Addict is a Turing tarpit where the only control flow is user-defined commands.

a A
 i 1
 i 1
 d
a B
 A 1
 A 1
 d
a C
 B 1
 B 1
 d
a D
 C 1
 C 1
 d
D b
D b
D b
D b
D b
D b
D b
C b
B b
d b
D q
D q
A q
c b
c q
c q
D q
C q
c q
n b
n q
n b
n q
A b
c b

This outputs {"":1235812358}. Try it in the online interpreter!

How it works

To golf answer space, I'm going to refer you to the sections Primer on Addict and Act I on "Hello, World!" in Addict. If you already know how that works, feel free to skip this part.

Act II

The rest of the program is devoted to outputting a valid JSON object in as few bytes as possible. In order to minimize the code, we can use the variables that are already set to output a number with the n command. The first step is then to set three variables to the two chars we need at first:

• b to 123, the char code of {
• q to 34, the char code of "

After these have been set, we output {"" one char at a time, then increment q by 24, resulting in 58, the charcode of :. We output that, then output the values of b and q twice, printing 1235812358. The last step is to increment b by 2 to change it to }, and then output it to finish.

If you can find any way to golf this program, please let me know!

Answer 23

Crystal, 23 bytes

puts %Q({"#{"a"*9}":0})

You can also avoid using %Q (and keep the same character count):

puts "{\"#{"a"*9}\":0}"

The above return:

{"aaaaaaaaa":0}

Which has exactly 15 characters.

Answer 24

Actually, 10 bytes

'}Qè;':@'{

Try it online!

Explanation:

'}Qè;':@'{
'}          push "}"
  Q         push this program's source code
   è        call Python's repr function (essentially just wraps the string in double-quotes)
    ;       duplicate
     ':@    push ":", swap with one copy of double-quoted source code
        '{  push "{"
            implicitly print each stack item, separated by newlines, starting with the top

Output:

{
"'}Qè;':@'{"
:
"'}Qè;':@'{"
}

Answer 25

Javascript, 14 bytes

'{"":'+1e9+'}'

Gives:

{"":1000000000}

I know that this doesn't actually print out anything, it merely returns. But so do all other Javascript solutions here.

Answer 26

RAGE!!!, 41 bytes

<rant>SCREAM"{\"12345\":54321}"!!!</rant>

Since the interpreter compiler transpiler on the esolangs page converts the code to Python 2 via mere string substitution, escaping double quotes should be okay.

Answer 27

ECMAScript 2015, 16 bytes

_=>`{"":${9e9}}`

It will run in most modern ECMAScript environments (eg. Firefox, Chrome, MS Edge, Opera, Node…).

Answer 28

JavaScript, 17 bytes

_=>'{"'+{}+'":0}'

outputs

{"[object Object]":0}

passes validator at jslint

This works because {} will implicitly be cast to string with the + concatenation, and calling toString on an object returns "[object Object]".

Answer 29

C#, 39 bytes

string j(){return"{\""+1.0/0+"\":42}";}

In C#, division of 0 with a double (hence the inclusion of .0), will result in Infinity.

Output:

{"Infinity":42}

Answer 30

Python 2, 13 bytes

print{"'":.1}

Outputs:

{"'": 0.10000000000000001}

Since tenths can't be stored exactly in binary Python outputs a 1 followed by 15 zeros followed by a 1 after the decimal point. Need double quotes around the single quote to not have the double quotes converted to single quotes (thanks to @JonathanAllan's comment to @xnor's answer).