Coding Challenge for CRG

CRG-question-1.js

// Write a program which gets a users timeline from Twitter and then prints out each odd item.

// Node.js

// Functional programming - No Loop - return a new array of odd values
function returnOdd(arr) {
  return arr.filter(function(el, index){
    return index % 2 ? el : null;
  })
}

// Add dependencies
var express = require('express');
var Twitter = require('twitter');

// Create express server
var server = express();

var client = new Twitter({
  consumer_key: TWITTER_CONSUMER_KEY,
  consumer_secret: TWITTER_CONSUMER_SECRET,
  access_token_key: TWITTER_ACCESS_TOKEN_KEY,
  access_token_secret: TWITTER_ACCESS_TOKEN_SECRET
});

server.get('/', function(req, res) {

  var params = {screen_name: 'screen_name'};

  // get user_timeline
  client.get('statuses/user_timeline', params, function(error, tweets, response) {
    if (!error) {

      // Print to console
      console.log(returnOdd(tweets));
      // Send Response
      res.send(returnOdd(tweets))
    }
  });
});

// Start server
server.listen(3000, function () {
  console.log('Server listening on port 3000!');
});

CRG-question-2.js

// Write a program which makes 4 AJAX calls in sequential order, one after the other, but never at the same time.

// ============================================================================
// Vanilla

// Wrapper for an ajax request with an optional callback + closure for counter
function ajax(callback){
  var counter = 0;
  var url = "path/to/resource/";
  var method = "GET";
  return function(){
    var r = new XMLHttpRequest();
    r.open(method, url , true);
    r.onreadystatechange = function () {
      if (r.readyState != 4 || r.status != 200) return;
      console.log("Success: " + (++counter) + ' : ' + r.responseText);
      if (typeof callback === 'function'){ callback(); }
    };
    r.send();
  }
}

// Make an array of requests
var request = [];
var howManyRequests = 4;
var a = ajax();
for ( var i = 0; i < howManyRequests; i++){
  request[i] = a
}

// Callback Hell
request[0](
  request[1](
    request[2](
      request[3]()
    )
  )
)

// ============================================================================
// Jquery + Promises + Recursion

function ajax(url, depth, howManyLeft){
  $.ajax(url)
    .done(function(){
      console.log("Success: " + (++depth))
      howManyLeft--;
      if(howManyLeft > 0){
        ajax(url, depth, howManyLeft);
      }
    }
  );
}
ajax('path/to/resource/', 0, 4 );

CRG-question-3.js

// Create a class system to represent a family hierarchy.

// JavaScript is an object-based language based on prototypes, rather than being class-based.

// Prototypal inheritance

// Animal Constructor
function Animal(type){
  this.type = type || '';
}

// Cat Constructor
// Cat inherits from Animal
function Cat(){
  Animal.call(this,'cat');
}
Cat.prototype = new Animal;
// Share sound amonst instances of Cat
Cat.prototype.sound = function(){
  console.log('Meow!');
}

// Dog Constructor
// Dog inherits from Animal
function Dog(){
  Animal.call(this,'dog');
}
Dog.prototype = new Animal;
// Share sound amonst instances of Dog
Dog.prototype.sound = function(){
  console.log('Woof!');
}

// Fish Constructor
// Fish inherits from Animal
function Fish(){
  Animal.call(this,'fish');
}
Fish.prototype = new Animal;

// Add new method that is shared across all instances that inherit from animal
Animal.prototype.whatType = function(){
  console.log(this.type);
}

// Creat instances
var garfield = new Cat();
garfield.sound(); // Meow!
var simon = new Cat();
simon.sound(); // Meow!

var snoopy = new Dog();
snoopy.sound(); // Woof!
garfield.sound(); // Meow!

var nemo = new Fish();
// nemo.sound(); // Won't work becasue the sound method does not exsist in prototypal chain for Fish

// Method + Properties inherited from Animal
garfield.whatType(); // cat
simon.whatType(); // cat
snoopy.whatType(); // dog
nemo.whatType(); // fish

CRG-question-4.js

// Write a program which can find and display all occurrences of string that
// matches a standard Australian phone number in the following format: (xx) (xxxx) (xxxx)

// Regex
function findPhoneNumber(text) {
  text = text.toString();

  // Regex - (xx) (xxxx) (xxxx)
  var myRe = /(\d{2})(\s{1})(\d{4})(\s{1})(\d{4})/gm;

  // Loop through and display found matches
  var match = [];
  var matches = [];
  while ((match = myRe.exec(text)) !== null) {
    var msg = 'Found ' + match[0] + '. ';
    // Display results
    matches.push(match[0]);
    console.log(msg);
  }

  console.log(matches);
}