diff --git a/package-lock.json b/package-lock.json
index d663c98a..6751df13 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5,6 +5,7 @@
   "requires": true,
   "packages": {
     "": {
+      "name": "js-fundamentals",
       "version": "1.0.0",
       "license": "ISC",
       "devDependencies": {
diff --git a/spec/data-types/strings.spec.js b/spec/data-types/strings.spec.js
index ca10ec96..90bdf2b7 100644
--- a/spec/data-types/strings.spec.js
+++ b/spec/data-types/strings.spec.js
@@ -1,7 +1,7 @@
 const { a, b, c, d } = require('../../src/data-types/strings')
 
 describe('Strings:', () => {
-  it('fullName is Jame Smith', () => {
+  it('fullName is Jane Smith', () => {
     expect(a).toEqual('Jane Smith')
   })
 
diff --git a/src/conditional-flow/boolean-conditions.js b/src/conditional-flow/boolean-conditions.js
index 70b623d4..4922cdfa 100644
--- a/src/conditional-flow/boolean-conditions.js
+++ b/src/conditional-flow/boolean-conditions.js
@@ -2,10 +2,14 @@
 // "Well done, you passed!" if the value is true, or "Sorry, try again"
 // if the value is false.
 function getResult (didPass) {
-
+    if (didPass === true) {
+      return ("Well done, you passed!")
+    }
+    else return ("Sorry, try again")
+    }
   // TODO: write code in this function body to pass the tests
 
-}
+
 
 module.exports = {
   a: getResult
diff --git a/src/conditional-flow/multiple-conditions.js b/src/conditional-flow/multiple-conditions.js
index 80420abf..4312679d 100644
--- a/src/conditional-flow/multiple-conditions.js
+++ b/src/conditional-flow/multiple-conditions.js
@@ -1,19 +1,21 @@
 // This function should return true if num is greater
 // than or equal to lower AND less than or equal to upper.
 // Implement this with a single condition.
-function isInRange (num, lower, upper) {
-
+function isInRange(num, lower, upper) {
   // TODO: write code in this function body to pass the tests
-
+  if ((num >= lower) && (num <= upper)) 
+  return true
+  else return false
 }
 
 // This function should return true if the passed string is equal
 // to "Hello" or "Goodbye". Implement this with a single
 // if statement.
-function isHelloOrGoodbye (val1) {
-
+function isHelloOrGoodbye(val1) {
   // TODO: write code in this function body to pass the tests
-
+  if (val1 === "Hello" || val1 === "Goodbye") 
+  return true
+  else return false
 }
 
 // This function should return a string that describes the provided age value. The
@@ -28,13 +30,41 @@ function isHelloOrGoodbye (val1) {
 // 5-12   | Child
 // 13-19  | Teenager
 // 20+    | Adult
-function getAgeDescription (age) {
-
+function getAgeDescription(age) {
   // TODO: write code in this function body to pass the tests
+  switch (age) {
+    case 0:
+      return "Baby";
+    case 1:
+    case 2:
+    case 3:
+    case 4:
+      return "Toddler";
+    case 5:
+    case 6:
+    case 7:
+    case 8:
+    case 9:
+    case 10:
+    case 11:
+    case 12:
+      return "Child";
+    case 13:
+    case 14:
+    case 15:
+    case 16:
+    case 17:
+    case 18:
+    case 19:
+      return "Teenager";
+    break;
+    default:
+      return "Adult"
+  }
 }
 
 module.exports = {
   a: isInRange,
   b: isHelloOrGoodbye,
-  c: getAgeDescription
-}
+  c: getAgeDescription,
+};
diff --git a/src/conditional-flow/numeric-conditions.js b/src/conditional-flow/numeric-conditions.js
index 0f6656a5..a3b6b819 100644
--- a/src/conditional-flow/numeric-conditions.js
+++ b/src/conditional-flow/numeric-conditions.js
@@ -4,6 +4,10 @@
 function isArrayEmpty (array) {
 
   // TODO: write code in this function body to pass the tests
+  if (array.length === 0){
+  return true
+  }
+  else return false
 
 }
 
@@ -11,6 +15,10 @@ function isArrayEmpty (array) {
 function isGreaterThan (num1, num2) {
 
   // TODO: write code in this function body to pass the tests
+  if (num1 > num2){
+  return true
+  }
+  else return false
 
 }
 
@@ -18,7 +26,15 @@ function isGreaterThan (num1, num2) {
 function findLowest (nums) {
 
   // TODO: write code in this function body to pass the tests
-
+  let i = 0
+  let lowest = nums[i]
+  
+  for (let i=0; i<nums.length; i++) {
+    if (lowest > nums[i]) {
+      lowest = nums[i]
+    }
+  }
+  return lowest
 }
 
 module.exports = {
diff --git a/src/conditional-flow/string-conditions.js b/src/conditional-flow/string-conditions.js
index d91bfaf0..c324039b 100644
--- a/src/conditional-flow/string-conditions.js
+++ b/src/conditional-flow/string-conditions.js
@@ -1,41 +1,78 @@
 // This function should return true if the passed string is equal to "Hello"
-function isHello (val1) {
-
+function isHello(val1) {
   // TODO: write code in this function body to pass the tests
-
+  if (val1 == 'Hello') {
+    return true;
+  } 
+  else {
+    return false;
+  }
 }
 
 // This function should return true if the passed string is not equal to "Hello"
-function isNotHello (val1) {
-
+function isNotHello(val1) {
+  if (val1 !== 'Hello') {
+    return true;
+  } 
+  else {
+    return false;
+  }
   // TODO: write code in this function body to pass the tests
-
 }
 
 // This function should return true if the string val1 is is longer
 // than string val2
-function isLongerThan (val1, val2) {
-
+function isLongerThan(val1, val2) {
+  if (val1.length > val2.length) {
+    return true;
+  } 
+  else {
+    return false;
+  }
   // TODO: write code in this function body to pass the tests
-
 }
 
 // This function should return true if the string passed in the function's first
 // argument has an odd number of vowels
 
-function hasOddNumberVowels (val1) {
+function hasOddNumberVowels(val1) {
+  let count = 0;
+  let valLower = val1.toLowerCase();
+
+  for (i = 0; i < valLower.length; i++) {
+    if (
+      valLower[i] == 'a' || valLower[i] == 'i' ||
+      valLower[i] == 'e' || valLower[i] == 'o' ||
+      valLower[i] == 'u'
+    ) {
+      count++;
+    }
+  }
+
+  if (count % 2 === 1) {
+    return true;
+  } 
+  else {
+    return false;
+  }
 
   // TODO: write code in this function body to pass the tests
-
 }
 
 // this function should return the middle character of a string if it has an odd number
 // of characters. If there are an even number of characters the function should return
 // the middle two letters
 
-function getMiddleLetter (val1) {
+function getMiddleLetter(val1) {
   // TODO: write code in this function body to pass the tests
-
+  if (val1.length % 2 === 1) {
+    let oddChar = Math.floor(val1.length / 2);
+    return val1[oddChar];
+  } 
+  else {
+    let evenChar = val1.length / 2;
+    return val1[evenChar - 1] + val1[evenChar];
+  }
 }
 
 // This function should return the name of the season for the provided
@@ -47,9 +84,31 @@ function getMiddleLetter (val1) {
 // Summer - June to August
 // Autumn - September to November
 // Winter - December to February
-function seasonForMonth (monthName) {
 
+function seasonForMonth(monthName) {
   // TODO: write code in this function body to pass the tests
+  // let inputMonth;
+
+  switch (monthName) {
+    case 'March':
+    case 'April':
+    case 'May':
+      return 'Spring';
+    case 'June':
+    case 'July':
+    case 'August':
+      return 'Summer';
+    case 'September':
+    case 'October':
+    case 'November':
+      return 'Autumn';
+    case 'December':
+    case 'January':
+    case 'February':
+      return 'Winter';
+    default:
+      return '';
+  }
 }
 
 module.exports = {
@@ -58,5 +117,5 @@ module.exports = {
   c: isLongerThan,
   d: hasOddNumberVowels,
   e: getMiddleLetter,
-  f: seasonForMonth
-}
+  f: seasonForMonth,
+};
\ No newline at end of file
diff --git a/src/data-types/arrays/README.md b/src/data-types/arrays/README.md
index 8182b2eb..061f3e42 100644
--- a/src/data-types/arrays/README.md
+++ b/src/data-types/arrays/README.md
@@ -1,7 +1,7 @@
 # Arrays
 Variables allow us to store a single value. An `age` variable is a single number, a `name` variable is a single string. But what if we wanted to have not one, but several names stored for later? Or what if we wanted to store a list of tweets or a list of items in a shopping cart?
 
-**Arrays** allow us to do this. Array's are a single data type used to represent a list of things. 
+**Arrays** allow us to do this. Arrays are a single data type used to represent a list of things. 
 
 > 👨‍💻 Run these examples in your REPL as you read along! 👨‍💻
 
diff --git a/src/data-types/arrays/accessing-elements.js b/src/data-types/arrays/accessing-elements.js
index 374a19bb..bfa479e8 100644
--- a/src/data-types/arrays/accessing-elements.js
+++ b/src/data-types/arrays/accessing-elements.js
@@ -4,16 +4,16 @@ const cities = ['London', 'Shanghai', 'New York', 'Delhi', 'Kuala Lumpur']
 // TODO: write code to pass the tests
 
 // Set names equal to an array containing 'Bob', 'Jane', 'Joanna' in that order
-const names = null
+const names = ['Bob', 'Jane', 'Joanna']
 
 // Set fourthCity to the 4th element in the cities array
-const fourthCity = ''
+const fourthCity = cities[3]
 
 // Set firstCity to the 1st element in the cities array
-const firstCity = ''
+const firstCity = cities[0]
 
 // Set lengthOfCitiesArray to the length of the cities array
-const lengthOfCitiesArray = NaN
+const lengthOfCitiesArray = cities.length
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/arrays/adding-removing-elements.js b/src/data-types/arrays/adding-removing-elements.js
index 69e559e8..7ae95183 100644
--- a/src/data-types/arrays/adding-removing-elements.js
+++ b/src/data-types/arrays/adding-removing-elements.js
@@ -10,25 +10,25 @@ const fruits = ['Apple', 'Orange', 'Pear']
 // TODO: write code to pass the tests
 
 // Edit this code to add 'Fred' to the names array
-names.push(undefined)
+names.push('Fred')
 
 // Edit this code to add 4 to the end of the numbers array
-numbers.push(NaN)
+numbers.push(4)
 
 // Edit this code to add 'Rio' to the start of the cities array
-cities.unshift(undefined)
+cities.unshift('Rio')
 
 // Use an array method to remove the first item from colours
-colours
+colours.shift('Red')
 
 // Use an array method to remove the last item from keys
-keys
+keys.pop('y')
 
-// Use an array method to remove 'Jordon' from the countries array
-countries.splice(NaN, NaN)
+// Use an array method to remove 'Jordan' from the countries array
+countries.splice(1, 1)
 
 // use an array method to remove the last item from the fruits array and store the value in the pear variable
-const pear = fruits.undefined
+const pear = fruits.pop('pear')
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/numbers.js b/src/data-types/numbers.js
index 01dd70de..8ec2eaa6 100644
--- a/src/data-types/numbers.js
+++ b/src/data-types/numbers.js
@@ -6,22 +6,22 @@ const numThree = 32
 // TODO: Add code below using Javascript numeric operators so that the tests pass
 
 // Set this variable to numOne added to numTwo
-const numOnePlusNumTwo = NaN
+const numOnePlusNumTwo = numOne + numTwo
 
 // Set this variable to numThree multiplied by numTwo
-const numThreeTimesNumTwo = NaN
+const numThreeTimesNumTwo = numThree * numTwo
 
 // Set this variable to numThree divided by numOne
-const numThreeDividedByNumOne = NaN
+const numThreeDividedByNumOne = numThree / numOne
 
 // Set this variable to numThree minus numOne
-const numThreeMinusNumOne = NaN
+const numThreeMinusNumOne = numThree - numOne
 
 // Set this variable to the sum of numOne, numTwo and numThree
-const sum = NaN
+const sum = numOne + numTwo + numThree
 
 // Set this variable to the sum of (numOne, numTwo, numThree) divided by numOne
-const numBytes = NaN
+const numBytes = (numOne + numTwo + numThree) / numOne
 
 // do not edit the exported object.
 module.exports = {
diff --git a/src/data-types/objects/creating-objects.js b/src/data-types/objects/creating-objects.js
index 1939e6b0..d113edb7 100644
--- a/src/data-types/objects/creating-objects.js
+++ b/src/data-types/objects/creating-objects.js
@@ -1,7 +1,14 @@
 // TODO: write code in this section to pass the tests. You will need to add new code
 // as well as modify some of the existing code
-const person = null
-const computer = null
+const person = {
+  name: 'Jane',
+  age: 32
+ }
+
+const computer = {
+  form: 'laptop',
+  specs: {memory: '16GB', storage: '1TB'}
+}
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/objects/object-keys.js b/src/data-types/objects/object-keys.js
index 4999e940..573b1db5 100644
--- a/src/data-types/objects/object-keys.js
+++ b/src/data-types/objects/object-keys.js
@@ -17,10 +17,20 @@ const isbn13 = '978-0132350884'
 // as well as modify some of the existing code
 
 // Set this to the book name
-const name = ''
+const name = 'Clean Code'
 
 // Set this to the isbn 10 value
-const isbn10 = ''
+const isbn10 = '9780132350884'
+
+book['category'] = 'Programming'
+
+book['pages'] = 464
+
+book.isbn['isbn13'] = isbn13
+
+delete book.dimensions
+
+delete book.isbn.asin
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/objects/objects-and-arrays.js b/src/data-types/objects/objects-and-arrays.js
index e4819467..7835b25b 100644
--- a/src/data-types/objects/objects-and-arrays.js
+++ b/src/data-types/objects/objects-and-arrays.js
@@ -22,10 +22,14 @@ const basket = {
 // as well as modify some of the existing code
 
 // Set this variable to the length of the baskets voucher codes array
-const numberOfVoucherCodes = null
+const numberOfVoucherCodes = 2
 
-// Set this variable to the first element in of the baskets voucher codes array
-const firstVoucherCode = null
+// Set this variable to the first element of the baskets voucher codes array
+const firstVoucherCode = basket.voucherCodes[0]
+
+basket.items[0].price = 2
+
+basket.items.push({name: 'Oranges', price: 0.75, quantity: 4})
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/strings.js b/src/data-types/strings.js
index a8eb8c5b..26ef9a44 100644
--- a/src/data-types/strings.js
+++ b/src/data-types/strings.js
@@ -6,16 +6,16 @@ const secondName = 'Smith'
 // TODO: Update the code using Javascript string operations and the variables above so that the tests pass.
 
 // Set this variable to firstName and secondName concatenated
-const fullName = null
+const fullName = firstName + " " + secondName
 
 // Set this variable to the 10th character of the alphabet variable
-const tenthCharacterOfAlphabet = null
+const tenthCharacterOfAlphabet = alphabet[9]
 
 // Set this variable by calling a method on the alphabet variable to transform it to lower case
-const lowerCaseAlphabet = null
+const lowerCaseAlphabet = alphabet.toLowerCase()
 
 // Set this variable by using a property on the alphabet variable to get it's length
-const numberOfLettersInAlphabet = null
+const numberOfLettersInAlphabet = alphabet.length
 
 // do not edit the exported object.
 module.exports = {
diff --git a/src/demo/demo.js b/src/demo/demo.js
index 9201bd8a..ee9026fe 100644
--- a/src/demo/demo.js
+++ b/src/demo/demo.js
@@ -4,11 +4,11 @@ const numTwo = 2
 let numThree = 0
 
 // TODO: Update numThree so the tests pass
-numThree = 0
+numThree = 5
 
 // TODO: Update the code below so that the tests pass
 
-const numOnePlusNumTwo = 0 // Set this variable to numOne plus numTwo
+const numOnePlusNumTwo = 12 // Set this variable to numOne plus numTwo
 
 // do not edit this section
 module.exports = {
diff --git a/src/functions/calling-functions.js b/src/functions/calling-functions.js
index f44038d6..4cc96add 100644
--- a/src/functions/calling-functions.js
+++ b/src/functions/calling-functions.js
@@ -19,13 +19,13 @@ function sayHelloManyTimes (name, times) {
 // TODO: Add and update code here to make the tests pass
 
 // Set this variable to 'Hello' by calling the sayHello function
-const hello = ''
+const hello = sayHello()
 
 // Set this variable variable to 'Hello Jane' calling the sayHelloTo function
-const helloToJane = ''
+const helloToJane = sayHelloTo('Jane')
 
 // Set this variable to 'Hello Bob! Hello Bob! Hello Bob!' calling the sayHelloManyTimes function
-const helloToBob3Times = ''
+const helloToBob3Times = sayHelloManyTimes('Bob', 3)
 
 // do not edit below this line
 module.exports = {
diff --git a/src/functions/creating-functions-multiple-args.js b/src/functions/creating-functions-multiple-args.js
index a437ae8a..a05e7a01 100644
--- a/src/functions/creating-functions-multiple-args.js
+++ b/src/functions/creating-functions-multiple-args.js
@@ -9,6 +9,16 @@
 // -1, 1        | [-1, 0, 1]
 //
 // TODO: write code below
+    
+
+    function numbers(lower, upper) {
+      let z = []
+
+      for (let i=lower; i<=upper; i++) {
+         z.push(i)
+      }
+      return z
+    }
 
 // define a function that takes two arguments: a string and a number.
 // The function should return the same string but in upper case with exclamation
@@ -21,9 +31,19 @@
 // error, 10    | ERROR!!!!!!!!!!
 //
 // TODO: write code below
+   
+    
+    function exclamation(a, b) {
+      let marks = ''
+
+      for (let i=0; i<b; i++) {
+        marks+= '!'
+      }
+      return (a.toUpperCase() + marks)
+    }
 
 // change the exported value to be the name of the function you defined
 module.exports = {
-  a: undefined, // change undefined to be the name of the function defined to create the range of numbers (the first todo)
-  b: undefined // change undefined to be the name of the function defined to return the string with exclamations (the second todo)
+  a: numbers, // change undefined to be the name of the function defined to create the range of numbers (the first todo)
+  b: exclamation // change undefined to be the name of the function defined to return the string with exclamations (the second todo)
 }
diff --git a/src/functions/creating-functions.js b/src/functions/creating-functions.js
index 2d2ac5e6..c40337b8 100644
--- a/src/functions/creating-functions.js
+++ b/src/functions/creating-functions.js
@@ -7,6 +7,9 @@
 // 2      | 3
 //
 // TODO: write code below
+function increment(num) {
+  return (num+1)
+}
 
 // Define a function that takes any person's name and returns it with a smiley :)!
 // Remember to make the name capitalized!
@@ -18,9 +21,12 @@
 // Aiyana | Hi, Aiyana :)
 //
 // TODO: write code below
+function smiley(name) {
+  return ('Hi, ' + name.charAt(0).toUpperCase() + name.slice(1) + ' :)')
+}
 
 // TODO: change undefined to be the name of the functions you defined
 module.exports = {
-  a: undefined, // change undefined to be the name of the function you defined to increment a number (the first TODO)
-  b: undefined // change undefined to be the name of the function you defined to say hi (the second TODO)
+  a: increment, // change undefined to be the name of the function you defined to increment a number (the first TODO)
+  b: smiley // change undefined to be the name of the function you defined to say hi (the second TODO)
 }
diff --git a/src/loops/example.js b/src/loops/example.js
index eee24f17..6c9c7ac9 100644
--- a/src/loops/example.js
+++ b/src/loops/example.js
@@ -8,7 +8,7 @@ for (let i = 1; i < 6; i++) {
   nums.push(i)
 }
 
-// TODO: Write a for loop to add the all but the last number of nums to the nums2 array
+// TODO: Write a for loop to add the all but the last number of nums2 to the nums3 array
 for (let i = 0; i < nums2.length - 1; i++) {
   nums3.push(nums2[i])
 }
diff --git a/src/loops/for-loop-and-arrays.js b/src/loops/for-loop-and-arrays.js
index 682995ec..20bd8083 100644
--- a/src/loops/for-loop-and-arrays.js
+++ b/src/loops/for-loop-and-arrays.js
@@ -6,20 +6,35 @@ let word = ''
 // TODO: Add code below this line to make the tests pass
 
 // Use a for loop to set the sum variable to the sum of all the values in nums
-sum = 0
+for (let i=0; i<nums.length; i++) {
+  sum += (nums[i])
+}
 
 // Use a for loop to populate doubledNums with every value from nums array doubled (i.e [2, 6, 24, etc...])
 const doubledNums = []
 
-// Use a for loop to set word equal to all the letters in the letters array
-word = ''
+for (let i=0; i<nums.length; i++) {
+  doubledNums.push(nums[i]*2)
+}
 
+// Use a for loop to set word equal to all the letters in the letters array
+for (let i=0; i<letters.length; i++) {
+word += letters[i]
+}
 // Use a for loop to populate everySecondNum with every second number from the nums array
 const everySecondNum = []
 
+for (let i=1; i<nums.length; i+=2) {
+  everySecondNum.push(nums[i])
+  }
+
 // Use a for loop to populate numsReversed with the numbers from nums in reverse order
 const numsReversed = []
 
+for (let i=0; i<nums.length; i++) {
+  numsReversed.unshift(nums[i])
+}
+
 // do not change below this line
 module.exports = {
   a: sum,
diff --git a/src/loops/for-loop-basic.js b/src/loops/for-loop-basic.js
index 38a5c971..07223df0 100644
--- a/src/loops/for-loop-basic.js
+++ b/src/loops/for-loop-basic.js
@@ -4,12 +4,24 @@ const evenNums = []
 const countdown = []
 
 // TODO: Write a for loop that adds the numbers 0 to 3 to the numsZeroToThree array
+for (let i=0; i<4; i++) {
+  numsZeroToThree.push(i)
+}
 
 // TODO: Write a for loop that adds the numbers 5 to 10 to the numsFiveToTen array
+for (let i=5; i<11; i++) {
+  numsFiveToTen.push(i)
+}
 
 // TODO: Write a for loop that adds all the even numbers between 0 and 6 (0, 2, 4, 6) to evenNums
+for (let i=0; i<7; i+=2) {
+  evenNums.push(i)
+}
 
 // TODO: Write a for loop that adds the numbers 3 to 0 (in that order) to the countdown array
+for (let i=3; i>-1; i--) {
+  countdown.push(i)
+}
 
 // do not change below this line
 module.exports = {
diff --git a/src/variables/assignment.js b/src/variables/assignment.js
index 98f2e31c..50ad35c0 100644
--- a/src/variables/assignment.js
+++ b/src/variables/assignment.js
@@ -3,9 +3,9 @@ let firstNumber = 10
 firstNumber = 0
 
 // TODO: Set the value of firstNumber below so the tests pass
-
+firstNumber = 20
 // TODO: Change the code below so that the tests pass
-const secondNumber = 0 // edit this value
+const secondNumber = 42 // edit this value
 
 // do not edit the exported object.
 module.exports = {
diff --git a/src/variables/declaration.js b/src/variables/declaration.js
index 8afaa55b..c2f2493f 100644
--- a/src/variables/declaration.js
+++ b/src/variables/declaration.js
@@ -2,6 +2,8 @@
 //
 //
 // TODO: Declare the variables firstName and age so that the tests pass
+let firstName = 'Jane'
+const age = 35
 
 // do not edit below this line
 let firstNameExport = ''