nickihastings

// Setup
var collection = {
    "2548": {
      "album": "Slippery When Wet",
      "artist": "Bon Jovi",
      "tracks": [ 
        "Let It Rock", 
        "You Give Love a Bad Name" 
      ]

nickihastings

function telephoneCheck(str) {
  // Good luck!
  
  var regex = /(^1(?=(\s\d{3}\s?-?\d{3}\s?-?\d{4}$)|(\s?\(\d{3}\)\s?-?\d{3}\s?-?\d{4}$)))|(^\((?=\d{3}\)\s?-?\d{3}\s?-?\d{4}$))|(^\d{3}(?=\s?-?\d{3}\s?\-?\d{4}$))/;
     
  return regex.test(str);

}

nickihastings

function addTogether() {
  //create a function that test whether arguments are numbers
  //if not a number return undefined, if it is return the number
  function checkArgs(val){
    if(typeof val !== 'number'){
      return undefined;
    }
    return val;
  }

nickihastings

function truthCheck(collection, pre) {
  // Is everyone being true?
  //set a variable to count the truthies
  var truthy = 0;
  //loop over the array and test for true
  //if it's true add one to truth
  for(var i = 0; i<collection.length; i++){
    if(collection[i][pre]){
      truthy ++;
    }

nickihastings

function binaryAgent(str) {
  var arr = str.split(' ');
  //var words = [];
  for(var i =0; i<arr.length; i++){
    arr[i] = parseInt(arr[i], 2);
    arr[i] = String.fromCharCode(arr[i]);
    //can also write the above as:
    //words.push(String.fromCharCode(parseInt(arr[i], 2))); 
    //parses first then converts to letter then pushes to array.
  }

nickihastings

function steamrollArray(arr) {
  // I'm a steamroller, baby
  var result = []; //store the resulting flat array
  //function to recursively flatten arrays inside of arrays.
  function flatten(arr){
    //for every item in the array check if it is an array itself
    for(var i = 0; i < arr.length; i++){
      if(Array.isArray(arr[i]) ){
        //if it is an array call the flatten function and concatinate the results

nickihastings

function dropElements(arr, func) {
  // Drop them elements.
  //shift() removes the element if it returns false
  //so loop over the array, test against the function
  //if it returns false remove the element, otherwise
  //return the array.
  while(arr.length > 0){
    var check = func(arr[0]);
    if(!check){

nickihastings

function findElement(arr, func) {
  var num = 0;
  //filter the array using the provided function, this will keep anything that returns true in an array;
  num = arr.filter(func);
  //return the first element in the new array.
  return num[0];
}

findElement([1, 2, 3, 4], function(num){ return num % 2 === 0; });

nickihastings

function smallestCommons(arr) {
  //sort the array ascending, so that a is always the smaller number
  arr.sort(function(a,b){
    return a-b;
  });
  //first find the GCD of the pair of numbers using the Euclidean Algorithm.
  //return the GCD
  function gcd(a, b){ 
    var x = a;

nickihastings

function sumPrimes(num) {
  var ints = [2]; //array to hold prime numbers
  
  //function to test if a number is a prime
  function isPrime(test){
    
    for(var i = 2; i < test; i++){
      
      if(test % i == 0){ //if there's no remainder it's not a prime
        return false; //not a prime number