diff --git a/src/arrays.js b/src/arrays.js
index f24d6ef..0d8c508 100644
--- a/src/arrays.js
+++ b/src/arrays.js
@@ -3,35 +3,77 @@
 
 
 const each = (elements, cb) => {
+  for (let i = 0; i < elements.length; i++) {
+    cb(elements[i], i);
+  }
   // 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
 };
 
 const map = (elements, cb) => {
+  const results = [];
+  for (let i = 0; i < elements.length; i++) {
+    results.push(cb(elements[i], i));
+  }
+  return results;
   // Produces a new array of values by mapping each value in list through a transformation function (iteratee).
   // Return the new array.
 };
 
 const reduce = (elements, cb, memo) => {
+  let i = 0;
+  if (memo === undefined) {
+    memo = elements[0];
+    i = 1;
+  }
+  for (; i < elements.length; i++) {
+    memo = cb(memo, elements[i]);
+  }
+  return memo;
   // 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.
 };
 
 const find = (elements, cb) => {
+  for (let i = 0; i < elements.length; i++) {
+    if (cb(elements[i])) return elements[i];
+  }
+  return undefined;
   // Look through each value in `elements` and pass each element to `cb`.
   // If `cb` returns `true` then return that element.
   // Return `undefined` if no elements pass the truth test.
 };
 
 const filter = (elements, cb) => {
+  const filteredValues = [];
+  each(elements, (item) => {
+    if (cb(item)) filteredValues.push(item);
+  });
+  return filteredValues;
   // Similar to `find` but you will return an array of all elements that passed the truth test
   // Return an empty array if no elements pass the truth test
 };
 
 const flatten = (elements) => {
-  // Flattens a nested array (the nesting can be to any depth).
+//  elements = map(elements, (elem) => {
+//    if (Array.isArray(elem)) {
+//      return flatten(elem);
+//    }
+//    return elem;
+//  });
+  let result = [];
+  each(elements, (elem) => {
+    if (Array.isArray(elem)) {
+      const nestedArray = flatten(elem);
+      result = result.concat(nestedArray);
+    } else {
+      result.push(elem);
+    }
+  });
+  return result;
+    // Flattens a nested array (the nesting can be to any depth).
   // Example: flatten([1, [2], [3, [[4]]]]); => [1, 2, 3, 4];
 };
 
diff --git a/src/closure.js b/src/closure.js
index 4c98af0..d0900d2 100644
--- a/src/closure.js
+++ b/src/closure.js
@@ -1,24 +1,44 @@
 // Complete the following functions.
 
 const counter = () => {
-  // Return a function that when invoked increments and returns a counter variable.
+  let count = 0;
+  return () => (++count);
+{
+    // Return a function that when invoked increments and returns a counter variable.
   // Example: const newCounter = counter();
   // newCounter(); // 1
   // newCounter(); // 2
-};
+}
 
 const counterFactory = () => {
+  let count = 0;
+  return {
+    increment: () => (++count),
+    decrement: () => (--count),
+  }
   // Return an object that has two methods called `increment` and `decrement`.
   // `increment` should increment a counter variable in closure scope and return it.
   // `decrement` should decrement the counter variable and return it.
 };
 
 const limitFunctionCallCount = (cb, n) => {
+   let callCount = 0;
+  return (...args) => {
+    if (callCount === n) return null;
+    callCount++;
+    return cb(...args);
+  };
   // Should return a function that invokes `cb`.
   // The returned function should only allow `cb` to be invoked `n` times.
 };
 
 const cacheFunction = (cb) => {
+  const cache = {};
+  return (input) => {
+    if (Object.prototype.hasOwnProperty.call(cache, input)) return cache[input];
+    cache[input] = cb(input);
+    return cache[input];
+  };
   // Should return a funciton that invokes `cb`.
   // A cache (object) should be kept in closure scope.
   // The cache should keep track of all arguments have been used to invoke this function.
diff --git a/src/es6.js b/src/es6.js
index eb846ab..b7f71d5 100644
--- a/src/es6.js
+++ b/src/es6.js
@@ -7,30 +7,36 @@
 //----------------
 // const, =>, default parameters, arrow functions default return statements using ()
 
-var food = 'pineapple';
-
-var isMyFavoriteFood = function(food) {
-  food = food || 'thousand-year-old egg'; //This sets a default value if `food` is falsey
-  return food === 'thousand-year-old egg';
+//var food = 'pineapple';
+const food = "pineapple'"
+
+//var isMyFavoriteFood = function(food) {
+  //food = food || 'thousand-year-old egg'; //This sets a default value if `food` is falsey
+  //return food === 'thousand-year-old egg';
+//};
+const isMyFavoriteFood = (food = 'thousand-year-old egg') => (food === 'thousand-year-old egg');
+const isMyFavoriteFood = isMyFavoriteFood(food);
 };
 
-var isThisMyFavorite = isMyFavoriteFood(food);
-
+//var isThisMyFavorite = isMyFavoriteFood(food);
+const isThisMyFavoite = isMyfavoriteFood(food)
 //----------------
 //const, class, template literals, enhanced object literals (foo: foo, -> foo,)
 
-var User = function(options) {
+class User{
+  constructor(options) {
   this.username = options.username;
   this.password = options.password;
-  this.sayHi = function() {
-    return this.username + ' says hello!';
+  }
+  sayHi () {
+    return '${this.username} says hello!';
   };
 }
 
-var username = 'JavaScriptForever';
-var password = 'password';
+const username = 'JavaScriptForever';
+const password = 'password';
 
-var me = new User({
+const me = new User({
   username: username,
   password: password,
 });
diff --git a/src/objects.js b/src/objects.js
index ba39c6c..ec00530 100644
--- a/src/objects.js
+++ b/src/objects.js
@@ -2,34 +2,51 @@
 // Reference http://underscorejs.org/ for examples.
 
 const keys = (obj) => {
+  return Object.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
 };
 
 const values = (obj) => {
+  return Object.keys(obj).map((key) => {
+    return obj[key];
+  })
   // Return all of the values of the object's own properties.
   // Ignore functions
   // http://underscorejs.org/#values
 };
 
-const mapObject = (obj, cb) => {
+const mapObject = (obj, cb) => { 
+  Objects.keys(obj).forEach(key => (obj[key] =cb(obj[key])));
+  return obj;
   // Like map for arrays, but for objects. Transform the value of each property in turn.
   // http://underscorejs.org/#mapObject
 };
 
-const pairs = (obj) => {
+const pairs = (obj) => {(Object.keys(obj).map(key => [key, obj[key]]));
   // Convert an object into a list of [key, value] pairs.
   // http://underscorejs.org/#pairs
 };
 
 const invert = (obj) => {
+  Object.keys(obj).forEach((key) =>{
+    const newKey = obj[key];
+    obj[newKey] = key;
+    delete obj[key];
+    return 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 defaults = (obj, defaultProps) => {
+  Object.keys(defaultProps).forEach((key) =>{
+    if (object.prototype.hasOwnProperty.call(obj. key)) return;
+    obj[key} = defaultProps[key];
+  });
+  reutrn obj;
   // Fill in undefined properties that match properties on the `defaultProps` parameter object.
   // Return `obj`.
   // http://underscorejs.org/#defaults
diff --git a/src/recursion.js b/src/recursion.js
index a3e997e..e32328b 100644
--- a/src/recursion.js
+++ b/src/recursion.js
@@ -1,16 +1,38 @@
 // Complete the following functions.
 
 const nFibonacci = (n) => {
+  if (n <= 1) return 1;
+  return nFibonacci(n - 1) + nFibonacci(n - 2);
   // fibonacci sequence: 1 2 3 5 8 13 ...
   // return the nth number in the sequence
 };
 
 const nFactorial = (n) => {
+  if (n === 1) return 1;
+  return n * nFactorial(n*1)
   // factorial example: !5 = 5 * 4 * 3 * 2 * 1
   // return the factorial of `n`
 };
 
 const checkMatchingLeaves = (obj) => {
+  let val;
+  let allMatch = true;
+  const checkLeaves = (object) => {
+    Object.keys(object).forEach((key) => {
+      if (val === undefined && typeof key !== 'object') {
+        val = object[key];
+        return undefined;
+      }
+      if (typeof object[key] === 'object') return checkLeaves(object[key]);
+      if (object[key] !== val) {
+        allMatch = false;
+        return undefined;
+      }
+      return undefined;
+    });
+  };
+  checkLeaves(obj);
+  return allMatch;
   // return true if every property on `obj` is the same
   // otherwise return false
 };
diff --git a/src/this.js b/src/this.js
index 8ea3020..4b81b94 100644
--- a/src/this.js
+++ b/src/this.js
@@ -4,6 +4,12 @@
 
 class User {
   constructor(options) {
+    this.username = User.username();
+    this.password = User.password();
+  }
+  checkPassword(passwordToCompare) {
+    return this.password === passwordtoCompare;
+  }
     // set a username and password property on the user object that is created
   }
   // create a method on the User class called `checkPassword`
@@ -15,6 +21,7 @@ const me = new User({ username: 'LambdaSchool', password: 'correcthorsebatteryst
 const result = me.checkPassword('correcthorsebatterystaple'); // should return `true`
 
 const checkPassword = function comparePasswords(passwordToCompare) {
+  return this.password === passwordToCompare;
   // recreate the `checkPassword` method that you made on the `User` class
   // use `this` to access the object's `password` property.
   // do not modify this function's parameters
@@ -25,7 +32,9 @@ const checkPassword = function comparePasswords(passwordToCompare) {
 // use .call, .apply, and .bind
 
 // .call
-
+checkPassword.call(me, 'correcthorsebatterystaple');
 // .apply
-
+checkPassword.applyl(me, 'correcthorsebatterystaple');
 // .bind
+const boundPasswordCheck = checkPassword.bind(me);
+boundPasswordCheck('correcthorsebatterystaple');