exercises.js

// Do not change any of the function names

function getBiggest(x, y) {
  // x and y are integers.  Return the larger integer
  // if they are the same return either one
  if(x > y){
    return x;
  }
  return y;
}

function greeting(language) {
  // return a greeting for three different languages:
  // language: 'German' -> 'Guten Tag!'
  // language: 'English' -> 'Hello!'
  // language: 'Spanish' -> 'Hola!'
  // if language is undefined return 'Hello!'
  if(language === 'German'){
    return 'Guten Tag!';
  }
  if(language === 'English'){
    return 'Hello!';
  }
  if(language === 'Spanish'){
    return 'Hola!';
  }
  return 'Hello!';
  

}

function isTenOrFive(num) {
  // return true if num is 10 or 5
  // otherwise return false
  if(num === 10 || num === 5){
    return true;
  }
  return false;
}

function isInRange(num) {
  // return true if num is less than 50 and greater than 20
  if(num < 50 && num > 20){
    return true;
  }
  return false;
}

function isInteger(num) {
  // return true if num is an integer
  // 0.8 -> false
  // 1 -> true
  // -10 -> true
  // otherwise return false
  // hint: you can solve this using Math.floor
  if(Math.floor(num) === num){
    return true;
  }
  return false;
}

function fizzBuzz(num) {
  // if num is divisible by 3 return 'fizz'
  // if num is divisible by 5 return 'buzz'
  // if num is divisible by 3 & 5 return 'fizzbuzz'
  // otherwise return num
  var numToWord = '';
  var isDivisible = false;
  if(num % 3 === 0){
    numToWord = numToWord + 'fizz';
    isDivisible = true;
  }
  if(num % 5 === 0){
    numToWord = numToWord + 'buzz';
    isDivisible = true;
  }
  if(isDivisible){
    return numToWord;
  }
  return num;

}

function isPrime(num) {
  // return true if num is prime.
  // otherwise return false
  // hint: a prime number is only evenly divisible by itself and 1
  // hint2: you can solve this using a for loop
  // note: 0 and 1 are NOT considered prime numbers
  for(var i = num - 1; i > 1; i--){
    if(num % i === 0){
      return false;
    }
  }
  if(num === 0 || num === 1){
    return false;
  }
  return true;
}

function returnFirst(arr) {
  // return the first item from the array
  return arr[0];
}

function returnLast(arr) {
  // return the last item of the array
  return arr[arr.length - 1];
}

function getArrayLength(arr) {
  // return the length of the array
  return arr.length;
}

function incrementByOne(arr) {
  // arr is an array of integers  
  // increase each integer by one
  // return the array
  for(var i = 0; i < arr.length; i++){
    arr[i] += 1;
  }
  return arr;
}

function addItemToArray(arr, item) {
  // add the item to the end of the array
  // return the array
  arr.push(item);
  return arr;
}

function addItemToFront(arr, item) {
  // add the item to the front of the array
  // return the array
  // hint: use the array method .unshift
  arr.unshift(item);
  return arr;
}

function wordsToSentence(words) {
  // words is an array of strings
  // return a string that is all of the words concatenated together
  // spaces need to be between each word
  // example: ['Hello', 'world!'] -> 'Hello world!'
  var sentence = '';
  for(var i = 0; i < words.length - 1; i++){
    sentence = sentence + words[i] + ' ';
  }
  sentence = sentence + words[words.length - 1];
  return sentence;
}

function contains(arr, item) {
  // check to see if item is inside of arr
  // return true if it is, otherwise return false
  if(arr.includes(item)){
    return true;
  }
  return false;
}

function addNumbers(numbers) {
  // numbers is an array of integers.
  // add all of the integers and return the value
  var sum = 0;
  for(var i = 0; i < numbers.length; i++){
    sum += numbers[i];
  }
  return sum;
}

function averageTestScore(testScores) {
  // testScores is an array.  Iterate over testScores and compute the average.
  // return the average
  var sum = 0;
  for(var i = 0; i < testScores.length; i++){
    sum += testScores[i];
  }
  return sum / testScores.length;
}

function largestNumber(numbers) {
  // numbers is an array of integers
  // return the largest integer
  var currentLargest = 0;
  for(var i = 0; i < numbers.length; i++){
    if(numbers[i] > currentLargest){
      currentLargest = numbers[i];
    }
  }
  return currentLargest;
}

// Do not modify code below this line.
// --------------------------------

module.exports = {
  getBiggest: getBiggest,
  greeting: greeting,
  isTenOrFive: isTenOrFive,
  isInRange: isInRange,
  isInteger: isInteger,
  fizzBuzz: fizzBuzz,
  isPrime: isPrime,
  returnFirst: returnFirst,
  returnLast: returnLast,
  getArrayLength: getArrayLength,
  incrementByOne: incrementByOne,
  addItemToArray: addItemToArray,
  addItemToFront: addItemToFront,
  wordsToSentence: wordsToSentence,
  contains: contains,
  addNumbers: addNumbers,
  averageTestScore: averageTestScore,
  largestNumber: largestNumber
};