Read And Write A Json File In Node.js

okay I have this json file: { 'joe': { 'name': 'joe', 'lastName': 'black' }, 'matt': { 'name': 'matt', 'lastName': 'damon' } }

Solution 1:

In node you can require json files:

var fs = require('fs');
var users = require('./names');

users.brad = {
  name: 'brad',
  lastName: 'pitt'
}

varstring = JSON.stringify(users,null,'\t');

fs.writeFile('./names.json',string,function(err) {
  if(err) returnconsole.error(err);
  console.log('done');
})

Optional async version without requiring:

var fs = require('fs');

fs.readFile('./names.json',{encoding: 'utf8'},function(err,data) {
  var users = JSON.parse(data);
   users.brad2 = { name: 'brad', lastName: 'pitt' };
  var string = JSON.stringify(users,null,'\t');

  fs.writeFile('./names.json',string,function(err) {
    if(err) returnconsole.error(err);
    console.log('done');
  })  
})

Solution 2:

The simple hint is: if you need to use process.nextTick, something is wrong. Leave that function to the library programmers! :)

Just move the function you call with nextTick to Until here...

nextTick does not wait until you read that file (that might take a few hundret ticks!), it just waits for the next tick. And that is available the nanosecond you call fs.read - because after fs.read the nodejs main loop is idle until either the kernel returns some information about that file or someone tells nodejs what to do on the next tick.