How to import values from Json Array in Javascript

i stored 3 twitter Api Keys in a Json file

{
  "twitter_api": [
    {
      "consumer_key":        "KEY",
      "consumer_secret":     "KEY",
      "access_token_key":    "KEY",
      "access_token_secret": "KEY"
    },
    {
      "consumer_key":        "KEY",
      "consumer_secret":     "KEY",
      "access_token_key":    "KEY",
      "access_token_secret": "KEY"
    },
    {
      "consumer_key":        "KEY",
      "consumer_secret":     "KEY",
      "access_token_key":    "KEY",
      "access_token_secret": "KEY"
    } 

Everytime i run my twitter application i want to Import 1 set of api keys randomly. i tried this code

var credentials = require('../settings.json').twitter_api[Math.floor(Math.random()*twitter_api.length)]; 

But i am getting an Error

anyone know how to do that correctly