MATLAB Answers

How to update json file with MATLAB?

72 views (last 30 days)
I have json file that is read by MATLAB script. I’m looking for a way to update the file since there are many to update. I know I can fixed the MATLAB script but I want to keep it and just fix the details in the json file.
I could not upload the json file since it does not accept it here. I converted to a txt one.
What I need to do is the following (in row 209)
For example. I have "HighPrice" :12000 and I want to change it to "HighPrice" :11000,
Anyway, MATLAB can fix this rather than doing it manually please?


Sign in to comment.

Accepted Answer

Kojiro Saito
Kojiro Saito on 10 Feb 2020
From R2016b, MATLAB can handle JSON format easily with jsondecode and jsonencode.
Here is a snippet to change the value of JSON and write to a file.
jsonText = fileread('Portfolio.json');
% Convert JSON formatted text to MATLAB data types (3x1 cell array in this example)
jsonData = jsondecode(jsonText);
% Change HighPrice value in Row 3 from 10000 to 12000
jsonData{3}.HighPrice = 12000;
% Convert to JSON text
jsonText2 = jsonencode(jsonData);
% Write to a json file
fid = fopen('Portfolio2.json', 'w');
fprintf(fid, '%s', jsonText2);


Yaser Khojah
Yaser Khojah on 10 Feb 2020
Thanks so much for your help :)
Emanuel Crespo
Emanuel Crespo on 14 Feb 2020
I , I've used this answer in my case but the text in the final .json file is all in a single line and not formatted as the initial one with spatials and line changes in the correct places. What do I need to do differently?

Sign in to comment.

More Answers (0)


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by