diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..388963e
Binary files /dev/null and b/.DS_Store differ
diff --git a/package.json b/package.json
index d23afbd..a69d3da 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "regenerator-runtime": "^0.10.3"
   },
   "dependencies": {
+    "babel-polyfill": "^6.26.0",
     "babel-preset-es2015": "^6.24.0",
     "eslint-config-airbnb": "^14.1.0"
   }
diff --git a/src/.DS_Store b/src/.DS_Store
new file mode 100644
index 0000000..daa70a2
Binary files /dev/null and b/src/.DS_Store differ
diff --git a/src/arrays.js b/src/arrays.js
index b995952..18bf8b7 100644
--- a/src/arrays.js
+++ b/src/arrays.js
@@ -8,17 +8,29 @@ const each = (elements, cb) => {
   // Iterates over a list of elements, yielding each in turn to the `cb` function.
   // This only needs to work with arrays.
   // based off http://underscorejs.org/#each
+  for (let i = 0; i < elements.length; i++) {
+    cb(elements[i], i);
+  }
 };
 
 const map = (elements, cb) => {
   // Produces a new array of values by mapping each value in list through a transformation function (iteratee).
   // Return the new array.
+  const newElements = [];
+  for (let i = 0; i < elements.length; i++) {
+    newElements.push(cb(elements[i], i, elements));
+  }
+  return newElements;
 };
 
 const reduce = (elements, cb, memo = elements.shift()) => {
   // Combine all elements into a single value going from left to right.
   // Elements will be passed one by one into `cb`.
   // `memo` is the starting value.  If `memo` is undefined then make `elements[0]` the initial value.
+  for (let i = 0; i < elements.length; i++) {
+    memo = cb(memo, elements[i]);
+  }
+  return memo;
 };
 
 const find = (elements, cb) => {
@@ -36,8 +48,18 @@ const filter = (elements, cb) => {
 const flatten = (elements) => {
   // Flattens a nested array (the nesting can be to any depth).
   // Example: flatten([1, [2], [3, [[4]]]]); => [1, 2, 3, 4];
+  let flat = [];
+  for (let i = 0; i < elements.length; i++) {
+    // if i !== array then push to flat
+    // else if i === array call flatten and concat to flatten
+    if (Array.isArray(elements[i])) {
+      flat = flat.concat(flatten(elements[i]));
+    } else {
+      flat.push(elements[i]);
+    }
+  }
+  return flat;
 };
-
 /* eslint-enable no-unused-vars, max-len */
 
 module.exports = {
diff --git a/src/class.js b/src/class.js
index 8276e29..d66a547 100644
--- a/src/class.js
+++ b/src/class.js
@@ -1,16 +1,42 @@
 // Create a class called User.
+class User {
 // The constructor of the class should have a parameter called `options`.
+  constructor(options) {
 // `options` will be an object that will have the properties `email` and `password`.
 // Set the `email` and `password` properties on the class.
+    this.email = options.email;
+    this.password = options.password;
 // Add a method called `comparePasswords`.  `comparePasswords` should have a parameter
+    this.comparePasswords = (potentialPassword) => {
 // for a potential password that will be compared to the `password` property.
-// Return true if the potential password matches the `password` property.  Otherwise return false.
+// Return true if the potential password matches the `password` property. Otherwise return false.
+      if (potentialPassword === this.password) {
+        return true;
+      } return false;
+    };
+  }
+}
 
-
-/* eslint-disable no-undef */ // Remove this comment once you write your classes.
+/* eslint-disable no-undef */ // Remove this comment once you write your classes. 
 
 
 // Create a class called `Animal` and a class called `Cat`.
+class Animal {
+// Animal and Cat should both have a parameter called `options` in their constructors.
+  constructor(options) {
+    this.age = options.age;
+    this.name = options.name;
+    this.growOlder = (years) => {
+      return this.age + 1;
+    };
+  }
+}
+
+class Cat extends Animal {
+  meow() {
+    return `${this.name} meowed!`;
+  }
+}
 // `Cat` should extend the `Animal` class.
 // Animal and Cat should both have a parameter called `options` in their constructors.
 // Animal should have the property `age` that's set in the constructor and the method
diff --git a/src/closure.js b/src/closure.js
index 2d6592f..bed5263 100644
--- a/src/closure.js
+++ b/src/closure.js
@@ -5,11 +5,18 @@ const counter = () => {
   // Example: const newCounter = counter();
   // newCounter(); // 1
   // newCounter(); // 2
+  let num = 0;
+  // create a function which increase num by one
+  const addOne = () => {
+    return num += 1;
+  }
+  // return the addOne to show the new value of num
+  return addOne();
 };
 
 const counterFactory = () => {
   // Return an object that has two methods called `increment` and `decrement`.
-  // `increment` should increment a counter variable in closure scope and return it.
+  // `increment` should increment a counter variable in closure scope and return it. 
   // `decrement` should decrement the counter variable and return it.
 };
 
diff --git a/src/es6.js b/src/es6.js
index eb846ab..9393b3c 100644
--- a/src/es6.js
+++ b/src/es6.js
@@ -7,50 +7,49 @@
 //----------------
 // const, =>, default parameters, arrow functions default return statements using ()
 
-var food = 'pineapple';
+let food = 'pineapple';
 
-var isMyFavoriteFood = function(food) {
+const isMyFavoriteFood = (food) => {
   food = food || 'thousand-year-old egg'; //This sets a default value if `food` is falsey
   return food === 'thousand-year-old egg';
 };
 
-var isThisMyFavorite = isMyFavoriteFood(food);
+let isThisMyFavorite = isMyFavoriteFood(food);
 
 //----------------
 //const, class, template literals, enhanced object literals (foo: foo, -> foo,)
 
-var User = function(options) {
-  this.username = options.username;
-  this.password = options.password;
-  this.sayHi = function() {
-    return this.username + ' says hello!';
-  };
-}
-
-var username = 'JavaScriptForever';
-var password = 'password';
-
-var me = new User({
-  username: username,
-  password: password,
-});
+const User = function (options) {
+    this.username = options.username;
+    this.password = options.password;
+    this.sayHi = () => {
+      return this.username + ' says hello!';
+    };
+  }
+  
+  var username = 'JavaScriptForever';
+  var password = 'password';
+  
+  var me = new User({
+    username: username,
+    password: password,
+  });
 
 // ----------------
 // let, const, =>, ... (spread operator)
 
-var addArgs = function () {
-  var sum = 0;
-  for (var i = 0; i < arguments.length; i++) {
-    sum += arguments[i];
-  }
-  return sum;
-};
-
-var argsToCb = function (cb) {
-  var args = Array.prototype.slice.call(arguments);
-  return cb.apply(null, args.splice(1));
-};
-
-var result = argsToCb(addArgs, 1, 2, 3, 4, 5); //result should be 15
-
+const addArgs = () => {
+    let sum = 0;
+    for (let i = 0; i < arguments.length; i++) {
+      sum += arguments[i];
+    }
+    return sum;
+  };
+  
+  let argsToCb = (cb) => {
+    let args = Array.prototype.slice.call(arguments);
+    return cb.apply(null, args.splice(1));
+  };
+  
+  let result = argsToCb(addArgs, 1, 2, 3, 4, 5); //result should be 15
 /* eslint-enable */
diff --git a/src/objects.js b/src/objects.js
index ba39c6c..5ffccc7 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -5,34 +5,72 @@ const keys = (obj) => {
   // Retrieve all the names of the object's properties.
   // Return the keys as strings in an array.
   // Based on http://underscorejs.org/#keys
+  return Object.getOwnPropertyNames(obj);
 };
 
 const values = (obj) => {
   // Return all of the values of the object's own properties.
   // Ignore functions
   // http://underscorejs.org/#values
+  return Object.values(obj);
 };
 
 const mapObject = (obj, cb) => {
   // Like map for arrays, but for objects. Transform the value of each property in turn.
   // http://underscorejs.org/#mapObject
+  // Get the values from the obj
+  const arrValues = Object.values(obj);
+  const arrKeys = Object.keys(obj);
+  let newValue = '';
+  // Loop thru the values
+  for (let i = 0; i < arrValues.length; i++) {
+    // send them each into the callback function to get new values
+    newValue = cb(arrValues[i]);
+    // add new values to the keys of the obj
+    obj[arrKeys[i]] = newValue;
+  }
+  return obj;
 };
 
 const pairs = (obj) => {
   // Convert an object into a list of [key, value] pairs.
   // http://underscorejs.org/#pairs
+  return Object.entries(obj);
 };
 
 const invert = (obj) => {
   // Returns a copy of the object where the keys have become the values and the values the keys.
   // Assume that all of the object's values will be unique and string serializable.
   // http://underscorejs.org/#invert
+  const arrKeys = Object.keys(obj);
+  const arrValues = Object.values(obj);
+  const newObj = {};
+  for (let i = 0; i < arrValues.length; i++) {
+    newObj[arrValues[i]] = arrKeys[i];
+  }
+  return newObj;
 };
 
 const defaults = (obj, defaultProps) => {
   // Fill in undefined properties that match properties on the `defaultProps` parameter object.
   // Return `obj`.
   // http://underscorejs.org/#defaults
+
+  // get the keys for obj
+  const arrKeys = Object.keys(obj);
+  // get the entries for defaultProps
+  const arrDefaultKeys = Object.keys(defaultProps);
+  const arrDefaultValues = Object.values(defaultProps);
+  // loop thru the keys for arrDefaultKeys and check to see if they are in arrKeys
+  for (let i = 0; i < arrDefaultKeys.length; i++) {
+    if (arrKeys.includes(arrDefaultKeys[i])) {
+      // That's good. Move on to the next one
+    } else {
+      // Since it's not included, add it to obj as a new property and values
+      obj[arrDefaultKeys[i]] = arrDefaultValues[i];
+    }
+  }
+  return obj;
 };
 
 /* eslint-enable no-unused-vars */
diff --git a/src/this.js b/src/this.js
index 8ea3020..fd64141 100644
--- a/src/this.js
+++ b/src/this.js
@@ -4,11 +4,18 @@
 
 class User {
   constructor(options) {
-    // set a username and password property on the user object that is created
+    // set a username and password property on the user object that is created 
+    this.username = options.username;
+    this.password = options.password;
+    this.checkPassword = (string) => {
+      if (string === this.password) {
+        return true;
+      } return false;
+    };
   }
   // create a method on the User class called `checkPassword`
   // this method should take in a string and compare it to the object's password property
-  // return `true` if they match, otherwise return `false`
+  // return `true` if they match, otherwise return `false` 
 }
 
 const me = new User({ username: 'LambdaSchool', password: 'correcthorsebatterystaple' });
@@ -19,13 +26,19 @@ const checkPassword = function comparePasswords(passwordToCompare) {
   // use `this` to access the object's `password` property.
   // do not modify this function's parameters
   // note that we use the `function` keyword and not `=>`
+  if (passwordToCompare === this.password) {
+    return true;
+  } return false;
 };
 
 // invoke `checkPassword` on `me` by explicitly setting the `this` context
 // use .call, .apply, and .bind
 
 // .call
+me.checkPassword.call(me);
 
 // .apply
+me.checkPassword.apply(me);
 
 // .bind
+me.checkPassword.bind(me)();