assignment 1-3.js

/* Part 1
*
* Define a function reverse() that computes
* the reversal of a string. For example,
* reverse("skoob") should return the
* string "books".
*/

function reverse(str){
  var x = '';
 for (var i = str.length; i > 0; i--)
   x += str[i];
 return x;
}
console.assert(reverse("books") === "skoob");
console.assert(reverse("we don't want no trouble") === "elbuort on tnaw t'nod ew");

/**
* Part 2
*
* Write a function findLongestWord() that takes an
* string returns the first, longest word in the array.
*
* i.e. findLongestWord("book dogs") should return "book"
*/

function findLongestWord(sentence){
      var str = sentence.split(" ");
      var longest = 0;
      var word = null;

      str.forEach(function(str) {
          if (longest < str.length) {
              longest = str.length;
              word = str;
          }
return word;
}
console.assert(findLongestWord("book dogs") === "book")
console.assert(findLongestWord("don't mess with Florida") === "Florida")
/**
* Part 3
*
* Write a function that calculates the sum of all the numbers in an array
*/

function sumOfArray(arr){
 var sum = 0; //placeholder//
 for(i = 0; i < arr.length; i ++) { //for loop to go through each variable in array//
 sum += arr[i]; //sum is sum + array 
 }
 return sum;
 }
console.assert(sumOfArray([1, 2]) === 3);
console.assert(sumOfArray([]) === 0);
console.assert(sumOfArray([1, 2, 3]) === 6);
console.assert(sumOfArray([10, 9, 8]) === 27);

/**
* Part 4
*
* Write a function that takes two numbers as
* arguments and computes the sum of those two numbers.
*/

function sum(a, b){
   return a + b;
 }

console.assert(sum(8, 11) === 19);
console.assert(sum(4, 100) === 104);

/**
* Part 5
*
* write a function that finds the Greatest Common Denominator of two numbers
* - if no GCD exists, return 1
*/

function GCD(a, b){
  if (b == 0) return a;
   else return (GCD (b, a % b));
}
//euclid's alog, punched into javascript. Remember this for the future.//
console.assert(GCD(5,1) === 1);
console.assert(GCD(15,3) === 3);
console.assert(GCD(15,5) === 5);
console.assert(GCD(50,20) === 10);

/**
* Part 6
*
* write a function that prints out the Least Common Multiple of two numbers
*/

function LCM(a, b){
   return (Math.abs(a * b) / GCD (a, b));
   //euclid's algo, using absolute value function//
}

console.assert(LCM(10,10) === 10)
console.assert(LCM(2,5) === 10)
console.assert(LCM(3,6) === 6)
console.assert(LCM(0,1) === 1)

Test