how to update a json file data in js code example

Example: update data in json using javascript

function setUsername(id, newUsername) {
  for (var i = 0; i < jsonObj.length; i++) {
    if (jsonObj[i].Id === id) {
      jsonObj[i].Username = newUsername;
      return;
    }
  }
}

// Call as
setUsername(3, "Thomas");