completed homework 2

README.md

@@ -4,11 +4,16 @@
 ---
 1. Feynman Writing Prompts - Write out explanations of the following concepts like you are explaining it to a 12 year old.  Doing this will help you quickly discover any holes in your understanding.  Ask your questions on Slack.
 
-	* `for`
-	* `&&`, `||`, `!`
-	* Arrays
-	* Git
-	* GitHub
+	* `for`  --- The for statement is used to start a block of code to loop over or iterate over something, such as an array or object.  
+
+	* `&&`, `||`, `!`  -- These are all logical operators in Javascript.  && is an operator that means 'and', || is an operator that means 'or' and ! is an operator that negates a statement.  For example != means not equal to.
+
+	* Arrays  --- Arrays are data structures used to store values in a computer's memory.  It is usually a collection of similar items, such as integers, strings or objects.
+
+	* Git  --- Git is the version control software that is used with repositories.
+
+
+	* GitHub  --- Github is an online repository for code.  
 
 
 2. Install git.  https://git-scm.com/downloads

exercises.js

@@ -3,6 +3,16 @@
 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;
+  }
+  else if (y > x) {
+    return y;
+  }
+  else {
+    return x || y;
+  }
+
 }
 
 function greeting(language) {
@@ -11,15 +21,60 @@ function greeting(language) {
   // language: 'English' -> 'Hello!'
   // language: 'Spanish' -> 'Hola!'
   // if language is undefined return 'Hello!'
+
+  switch (language) {
+    case 'German': return 'Guten Tag!';
+
+
+    case 'English': return 'Hello!';
+
+
+    case 'Spanish': return 'Hola!';
+
+
+    default: return 'Hello!';
+
+  }
+
 }
 
+
+//   if (language === 'German') {
+//     return 'Guten Tag!';
+//   }
+//   else if (language === 'English') {
+//     return 'Hello!';
+//   }
+//   else if (language === 'Spanish') {
+//     return 'Hola!';
+//   }
+//   else {
+//     return 'Hello!';
+//   }
+
+// }
+
 function isTenOrFive(num) {
   // return true if num is 10 or 5
   // otherwise return false
+  switch (num) {
+    case 5: return true;
+
+    case 10: return true;
+
+    default: return false;
+  }
+
 }
 
 function isInRange(num) {
   // return true if num is less than 50 and greater than 20
+  if ((num < 50) && (num > 20)) {
+    return true;
+  }
+  else {
+    return false;
+  }
 }
 
 function isInteger(num) {
@@ -29,77 +84,208 @@ function isInteger(num) {
   // -10 -> true
   // otherwise return false
   // hint: you can solve this using Math.floor
+
+  if (num === Math.floor(num)) {
+    return true;
+  }
+  else {
+    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
+
+  if ((num % 3 === 0) && (num % 5 === 0)) {
+    return 'fizzbuzz';
+  }
+
+  else if (num % 3 === 0) {
+    return 'fizz';
+  }
+  else if (num % 5 === 0) {
+    return 'buzz';
+  }
+  else {
+    return num;
+  }
+
+
+
 }
 
-function isPrime(num) {
+function isPrime(n) {
   // 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
+
+  if (n<2) {
+    return false;
+  }
+  else if (n === 2) {
+    return true;
+  }
+  for (var i = 2; i < n; i++) {
+    if (n%i === 0) {
+      return false;
+    }
+    else if (i === n-1) {
+      return true;
+    }
+  }
 }
 
+
+//   var i;
+
+//     if(num === 1) { return false;}
+//     else if(num == 2) { return true;}
+//     else if(num == 3) { return true;}
+//     else { 
+//         for(i=Math.floor(Math.sqrt(num));i>=2;i--){
+//             //console.log(i);//maybe another var in here? 
+//                 if(num%i ==0 || num%2 ==0 || num%3 == 0) {return false;} 
+//         } 
+//         }
+//     return true;
+// }
+
+
+
+
+
+
+  // if ((num >= 2) && (num % num === 0) && (num % 1 === 0)) {
+  //   for (var i = 3; i < num; i += 2) {
+
+  //   }
+  //   return true;
+  // }
+  // else {
+  //   return false;
+  // }
+
+  // if ((Math.sqrt(num) === 0) || (Math.sqrt(num) === 1))  {
+  //   return false;
+  // }
+  // else if ((num % num === 0) && (num % 1 === 0)) {
+  //   return true;
+  // }
+  // else {
+  //   return false;
+  // }
+
+
+
+// }
+
 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.slice(-1)[0];
 }
 
 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]++;
+  }
+  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!'
+
+  return words.join(' ');
+
 }
 
 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;
+  }
+  else {
+    return false;
+  }
 }
 
 function addNumbers(numbers) {
   // numbers is an array of integers.
   // add all of the integers and return the value
+
+  var sum = numbers.reduce(function(a, b){
+    return a + b;
+  });
+
+  return sum;
+
 }
 
 function averageTestScore(testScores) {
   // testScores is an array.  Iterate over testScores and compute the average.
   // return the average
+
+var sum = testScores.reduce(function(a, b) {
+  return a + b;
+});
+
+var avg = sum / testScores.length;
+
+return avg;
+
 }
 
 function largestNumber(numbers) {
   // numbers is an array of integers
   // return the largest integer
+
+  var largest = Math.max.apply(0, numbers);
+
+  // var largest = numbers.reduce(function(a, b) {
+  //   return Math.max(a, b);
+  // });
+
+  return largest;
+
+
+
 }
 
 // Do not modify code below this line.