Convert Struct to Readable JSON(Pretty Print)

Every struct I pass to jsonecode gets converted to a 1 by N char array with no newline chacters. Therefore, when I export the json as to a text file I only have one line. The file is not easly readble because I have to scroll the JSON text horizontaly. How can I make jsonencode's output easily readable(pretty print)?

I get this.

{ "firstName": "John", "lastName": "Smith", "age": 25, "address": { "streetAddress": "3 Apple Hill Dr", "city": "Natick", "state": "MA", "postalCode": "01760" }, "phoneNumber": [ { "type": "home", "number": "123 456 7890" }, { "type": "cell", "number": "098 765 4321" } ] }

I want something like this.

{

"firstName": "John",

"lastName": "Smith",

"age": 25,

"address":

{

"streetAddress": "3 Apple Hill Dr",

"city": "Natick",

"state": "MA",

"postalCode": "01760"

},

"phoneNumber":

[

{

"type": "home",

"number": "123 456 7890"

},

{

"type": "cell",

"number": "098 765 4321"

}

]

}

[Jan Zalewski]

I have the same problem

according to documentation jsonencode has "PrettyPrint" value that shoudl do just that, unfortunately this doesn't seem to be working on newer version of matlab

[Martin]

I would like to see the PrettyPrint option supported as well. Is it introduced in release 2021a then?

[Sean Bone]

@Martin yes, it was introduced in R2021a.

[Davide Serina]

ciao, come si fa ad ottenere una struttura come quella che hai scritto partendo da una struttura su matlab?! cioè non riesco a fare gli annidamenti. bisogna usare un ciclo for???

[Sean Bone]

Ciao @Davide Serina, la tua domanda si riferisce a come creare una struttura annidata in MATLAB o a come convertire una struttura annidata in JSON? Oppure ancora a come convertire una struttura MATLAB in JSON con le indentature per rappresentare gli annidamenti?

Answer 1

[Sean Bone]

In more recent Matlab versions, you can do the following:

jsonencode(data, "PrettyPrint", true);

Note that this option was only introduced in Matlab R2021a, despite the documentation for jsonencode not mentioning this explicitly.

[ILoveMATLAB]

I guess I will accept this anwser; although, I was using an older version of matlab when I wrote this question.

Answer 2

[Gaurav Garg]

Hi,

You can find a function which can help you resolve the problem you are facing in this file.

[Laurel Keyes]

This file is helpful but not if you have nested structures. I use a quick and dirty method, where you just string-replace the commas or brackets like so:

% assuming your structure is saved to val:
str = jsonencode(val);
% add a return character after all commas:
new_string = strrep(str, ',', ',\n');
% add a return character after curly brackets:
new_string = strrep(new_string, '{', '{\n')
% etc...
% Write the string to file
fid = fopen("filename.json",'w')
fprint(fid, new_string); 
fclose(fid);

This method will not indent but does allow a slightly better formatting, no matter the structure of your json