How do I update the data saved in a JSON file using JavaScript?

Question

How do I update the data saved in a JSON file using JavaScript?

for example: If i have a JSON file called 'person.json', looking like:

{ "Person": [ { "Firstname": "John", "Lastname": "Doe" } ] }

and I would like to append as new data set the name 'John Smith'. How could I do this using JavaScript?

EDIT: Now I tried to use 'fs.readFile()' to read my JSON file. The application I develop is a hybrid app using cordova. If i use 'fs.readFile()' i get the error 'Uncaught ReferenceError: fs is not defined'. I tried to fix this problem by adding the line 'var fs = Npm.require('fs');'. But this causes also an error: 'Uncaught ReferenceError: Npm is not defined'

Is this error caused because npm is not available on a smartphone? And how can i fix this problem?

Answer 1

You can simply use JSON.parse(data) to parse the JSON string into an object. Then when you're done, use JSON.stringify(object) to convert it into a JSON string.

You can write and read files with fs link .