Jazarro

var fileSystemModule = require("file-system");
var fileName = "persistedFile.json";

var file = fileSystemModule.knownFolders.documents().getFile(fileName);
var data = [{"id": "1", "value": "NativeScript"}, ...]; 

// write data to the file, converted to a JSON string first
file.writeText(JSON.stringify(data));

// read data from the file