#algorithm scripting

Return true if the string in the first element of the array contains all of the letters of the string in the second element of the array.

For example, ["hello", "Hello"], should return true because all of the letters in the second string are present in the first, ignoring case.

The arguments ["hello", "hey"] should return false because the string "hello" does not contain a "y".

Lastly, ["Alien", "line"], should return true because all of the letters in "line" are present in "Alien".

function mutation(arr) {

 var secondWord = arr[0].toLowerCase();

 var firstWord = arr[1].toLowerCase();

 for (i = 0; i < firstWord.length; i++) {    if (secondWord.indexOf(firstWord[i]) === -1) {       return false; }

   }  return true; }

mutation(["Mary", "Army"]);

use indexOf to solve this

Write a function that splits an array (first argument) into groups the length of size (second argument) and returns them as a two-dimensional array.

function chunkArrayInGroups(arr, size) {

 var newArray = [];

 for (var i = 0; i < arr.length; i+=size) {    newArray.push(arr.slice(i , i+size));  }  return newArray; }

chunkArrayInGroups(["a", "b", "c", "d"], 2);

First, we create an empty array newArray where we will store our ‘chunks’.

The for loop starts at zero, increments by size each time through the loop, and stops when it reaches arr.length.

Note that this for loop does not loop through arr. Instead, we are using the loop to generate numbers we can use as indices to slice the array in the right locations.

Inside our loop, we create each chunk using arr.slice(i, i+size), and add this value with newArray.push()

In this algorithm scripting activity, we used the substr() method to confirm if the ending of the sentence or word matched the given target word or letter. By taking length of the target word and turning it negative, we could then return true or false to solve the challenge.

function confirmEnding(str, target) { return str.substr(-target.length) === target;}

confirmEnding("Open sesame", "same");

function palindrome(str) {  // lower case, remove symbols  var first = str.toLowerCase().replace(/[^A-Za-z0-9]/g, "");

 // split the word or sentence, reverse and then join  var second = first.split("").reverse().join("");

 // check to see if the lowercased, alphanumeric var == the reversed one  if (first == second) {    return true;  }

 return false; }

Recursion is the method of calling a function inside of itself in order to perform a given action. In this example, we are factorializing a given number (multiplying the number by every number less than itself but greater than one). Recursion works here by simplifying the function which could be slightly longer by using a for loop).

function factorialize(num) {

 if(num === 0) {    return 1;}

 return num * factorialize(num - 1);

}

factorialize(5);

For loop (alt):

function factorialize(num) {  

      for (a = 1;num >= 1; num--) { 

         a = num * a;  

         }  

      return a; 

}