mjzone

var myString = "Manoj";
var myNumber = 42;

myString = 32;

console.log('42' - 2); // Result: 40
console.log('42' + 2); // Result: 422 gotcha! (Javascript infers the type of variable at Runtime.)
                       // Javascript assumes you want to concat two strings.
var anotherString = '42'
console.log(parseInt(anotherString, 10) +  2); // Be explicit about your variable types.

mjzone

console.log('Manoj'.length); // 5 (String is an object. So you can access its properties.)

mjzone

var person = new Object();
person.name = 'Manoj';
console.log(person) //Result: Object {name: "Manoj"} 

var ages = new Array(10);
console.log(ages) // Result: [,,,,,,,,,,] gotcha!

// Always use JSON format. 
var person = {
  name: 'Manoj'

mjzone

// Functions are 'first-class' objects.
var myFunction = function(){
  console.log("I have been called.");
}
myFunction.firstName = 'Manoj'; // we can attach attributes to functions because they are also objects.
console.log(myFunction);

// Functions can be anonymous.
setTimeout(function(){
  console.log("hello, i have been called after 1 second.")

mjzone

var array1 = [1,2,3];
var array2 = [];

for(var i=0; i< array1.length; i++){
  array2.push(array1[i]*2);
}

console.log(array2);

mjzone

A curated list of AWS resources to prepare for the AWS Certifications

A curated list of awesome AWS resources you need to prepare for the all 5 AWS Certifications. This gist will include: open source repos, blogs & blogposts, ebooks, PDF, whitepapers, video courses, free lecture, slides, sample test and many other resources.

For more about AWS and AWS Certifications and updates to this Gist you should follow me @leonardofed

---

mjzone

const AWS = require('aws-sdk');
const CognitoUserPool = require('amazon-cognito-identity-js-node').CognitoUserPool;
const CognitoUserSession = require('amazon-cognito-identity-js-node').CognitoUserSession;
const CognitoUser = require('amazon-cognito-identity-js-node').CognitoUser;
const CognitoIdToken = require('amazon-cognito-identity-js-node').CognitoIdToken;
const CognitoAccessToken = require('amazon-cognito-identity-js-node').CognitoAccessToken;
const CognitoRefreshToken = require('amazon-cognito-identity-js-node').CognitoRefreshToken;

const cfg = require('config').config;
const COGNITO_IDENTITY_POOL_ID = cfg.COGNITO_IDENTITY_POOL_ID;

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let _ = require('underscore');
let USERS_TABLE = process.env.USERS_TABLE;

module.exports.migrateUser = async (event, context) => {
  if (event.triggerSource == 'UserMigration_Authentication') {
    // check if the user exists on mlab
    if (event.userName && event.userName.length) {
      let db = await dbHelper.connectToDatabase(MONGODB_URI, DB_NAME);
      // lookup on the mongodb
      lookUp(db, event.userName).then(

mjzone

// The default access level of the uploads is "public"
const handleChange = async (e) => {
  const file = e.target.files[0];
  await Storage.put('picture.jpg', file, {
        contentType: 'image/jpg'
  });
}

// HTML
<input type="file" accept='image/jpg' onChange={(evt) => handleChange(evt)} />

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// Set the "level" attribute value to "protected"
const handleChange = async (e) => {
  const file = e.target.files[0];
  await Storage.put('picture.jpg', file, {
        contentType: 'image/jpg',
        level: 'protected'
  });
}

// HTML