diff --git a/src/conditional-flow/boolean-conditions.js b/src/conditional-flow/boolean-conditions.js
index 70b623d4..68f6954e 100644
--- a/src/conditional-flow/boolean-conditions.js
+++ b/src/conditional-flow/boolean-conditions.js
@@ -2,9 +2,10 @@
 // "Well done, you passed!" if the value is true, or "Sorry, try again"
 // if the value is false.
 function getResult (didPass) {
-
-  // TODO: write code in this function body to pass the tests
-
+  if (didPass) {
+    return "Well done, you passed!"
+  }
+  return "Sorry, try again"
 }
 
 module.exports = {
diff --git a/src/conditional-flow/multiple-conditions.js b/src/conditional-flow/multiple-conditions.js
index 80420abf..c73be410 100644
--- a/src/conditional-flow/multiple-conditions.js
+++ b/src/conditional-flow/multiple-conditions.js
@@ -2,18 +2,17 @@
 // than or equal to lower AND less than or equal to upper.
 // Implement this with a single condition.
 function isInRange (num, lower, upper) {
-
-  // TODO: write code in this function body to pass the tests
-
+  return (num >= lower && num <= upper)
 }
 
 // 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) {
-
-  // TODO: write code in this function body to pass the tests
-
+  if (val1 === 'Hello' || val1 === 'Goodbye') {
+    return true
+  }
+  return false
 }
 
 // This function should return a string that describes the provided age value. The
@@ -29,8 +28,23 @@ function isHelloOrGoodbye (val1) {
 // 13-19  | Teenager
 // 20+    | Adult
 function getAgeDescription (age) {
-
-  // TODO: write code in this function body to pass the tests
+  let description = ''
+  if (age === 0) {
+    description = 'Baby'
+  }
+  else if (age < 5) {
+    description = 'Toddler'
+  }
+  else if (age < 13) {
+    description = 'Child'
+  }
+  else if (age < 20) {
+    description = 'Teenager'
+  }
+  else {
+    description = 'Adult'
+  }
+  return description
 }
 
 module.exports = {
diff --git a/src/conditional-flow/numeric-conditions.js b/src/conditional-flow/numeric-conditions.js
index 0f6656a5..4c505b87 100644
--- a/src/conditional-flow/numeric-conditions.js
+++ b/src/conditional-flow/numeric-conditions.js
@@ -2,23 +2,23 @@
 
 // This function should return true if there are no elements in the array, false otherwise
 function isArrayEmpty (array) {
-
-  // TODO: write code in this function body to pass the tests
-
+  return (array.length === 0)
 }
 
 // This function should return true if num1 is greater than num2, false otherwise
 function isGreaterThan (num1, num2) {
-
-  // TODO: write code in this function body to pass the tests
-
+  return (num1 > num2)
 }
 
 // This function should return the lowest number in the passed array
 function findLowest (nums) {
-
-  // TODO: write code in this function body to pass the tests
-
+  let smallest = nums[0]
+  for (let i = 1; i < nums.length; i++) {
+    if (nums[i] < smallest) {
+      smallest = nums[i]
+    }
+ }
+ return smallest
 }
 
 module.exports = {
diff --git a/src/conditional-flow/string-conditions.js b/src/conditional-flow/string-conditions.js
index d91bfaf0..bafcc8e5 100644
--- a/src/conditional-flow/string-conditions.js
+++ b/src/conditional-flow/string-conditions.js
@@ -1,32 +1,31 @@
 // This function should return true if the passed string is equal to "Hello"
 function isHello (val1) {
-
-  // TODO: write code in this function body to pass the tests
-
+  return (val1 === 'Hello')
 }
 
 // This function should return true if the passed string is not equal to "Hello"
 function isNotHello (val1) {
-
-  // TODO: write code in this function body to pass the tests
-
+  return (val1 !== 'Hello')
 }
 
 // This function should return true if the string val1 is is longer
 // than string val2
 function isLongerThan (val1, val2) {
-
-  // TODO: write code in this function body to pass the tests
-
+  return (val1.length > val2.length)
 }
 
 // This function should return true if the string passed in the function's first
 // argument has an odd number of vowels
 
 function hasOddNumberVowels (val1) {
-
-  // TODO: write code in this function body to pass the tests
-
+  const VOWELS = ['a', 'e', 'i', 'o', 'u']
+  let total = 0
+  for (let i = 0; i < val1.length; i++) {
+    if (VOWELS.includes(val1[i].toLowerCase())) {
+      total++
+    }
+  }
+  return Boolean(total % 2)
 }
 
 // this function should return the middle character of a string if it has an odd number
@@ -34,8 +33,16 @@ function hasOddNumberVowels (val1) {
 // the middle two letters
 
 function getMiddleLetter (val1) {
-  // TODO: write code in this function body to pass the tests
-
+  let mid = Math.round(val1.length / 2)
+  let chars = ""
+  if (val1.length % 2 === 0) {
+    chars += val1[mid - 1]
+    chars += val1[mid]
+  }
+  else {
+    chars += val1[mid - 1]
+  }
+  return chars
 }
 
 // This function should return the name of the season for the provided
@@ -48,8 +55,32 @@ function getMiddleLetter (val1) {
 // Autumn - September to November
 // Winter - December to February
 function seasonForMonth (monthName) {
-
-  // TODO: write code in this function body to pass the tests
+  // let season = ""
+  switch (monthName) {
+    case 'March':
+    case 'April':
+    case 'May':
+      season = "Spring";
+      break;
+    case 'June':
+    case 'July':
+    case 'August':
+      season = "Summer";
+      break;
+    case 'September':
+    case 'October':
+    case 'November':
+      season = "Autumn";
+      break;
+    case 'December':
+    case 'January':
+    case 'February':
+      season = "Winter";
+      break;
+    default:
+      season = "";
+  }
+  return season
 }
 
 module.exports = {
@@ -59,4 +90,4 @@ module.exports = {
   d: hasOddNumberVowels,
   e: getMiddleLetter,
   f: seasonForMonth
-}
+}
\ No newline at end of file
diff --git a/src/data-types/arrays/accessing-elements.js b/src/data-types/arrays/accessing-elements.js
index 374a19bb..4dbc3403 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 = 'Delhi'
 
 // Set firstCity to the 1st element in the cities array
-const firstCity = ''
+const firstCity = 'London'
 
 // 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..80fa3d2e 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()
 
 // Use an array method to remove the last item from keys
-keys
+keys.pop()
 
 // Use an array method to remove 'Jordon' from the countries array
-countries.splice(NaN, NaN)
+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()
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/numbers.js b/src/data-types/numbers.js
index 01dd70de..bd9a083d 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 = sum / 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..30d53df1 100644
--- a/src/data-types/objects/creating-objects.js
+++ b/src/data-types/objects/creating-objects.js
@@ -1,7 +1,16 @@
 // 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..9e815495 100644
--- a/src/data-types/objects/object-keys.js
+++ b/src/data-types/objects/object-keys.js
@@ -17,10 +17,19 @@ 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'
+
+book.category = 'Programming'
+
+book.pages = 464
+
+book.isbn.isbn13 = '978-0132350884'
+
+delete book.isbn.asin
+delete book.dimensions
 
 // Set this to the isbn 10 value
-const isbn10 = ''
+const isbn10 = '9780132350884'
 
 // 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..bfb046f5 100644
--- a/src/data-types/objects/objects-and-arrays.js
+++ b/src/data-types/objects/objects-and-arrays.js
@@ -4,12 +4,17 @@ const basket = {
     {
       name: 'Apple',
       quantity: 10,
-      price: 1
+      price: 2
     },
     {
       name: 'Lemon',
       quantity: 2,
       price: 0.5
+    },
+    {
+      name: 'Oranges',
+      quantity: 4,
+      price: 0.75
     }
   ],
   voucherCodes: [
@@ -22,10 +27,10 @@ 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 = basket.voucherCodes.length
 
 // Set this variable to the first element in of the baskets voucher codes array
-const firstVoucherCode = null
+const firstVoucherCode = basket.voucherCodes[0]
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/strings.js b/src/data-types/strings.js
index a8eb8c5b..c79ad51a 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 = "J"
 
 // 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/functions/calling-functions.js b/src/functions/calling-functions.js
index f44038d6..e6bbf762 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..6bcdb142 100644
--- a/src/functions/creating-functions-multiple-args.js
+++ b/src/functions/creating-functions-multiple-args.js
@@ -9,7 +9,13 @@
 // -1, 1        | [-1, 0, 1]
 //
 // TODO: write code below
-
+function createArray(lower, upper) {
+  let anArray = []
+  for (let i = lower; i <= upper; i++) {
+    anArray.push(i)
+  }
+  return anArray
+}
 // 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
 // marks appended to the end. The number of exclamation marks should be
@@ -21,9 +27,16 @@
 // error, 10    | ERROR!!!!!!!!!!
 //
 // TODO: write code below
+function shout (str, num) {
+  let output = str.toUpperCase()
+  for (let i = 0; i < num; i++) {
+    output += "!"
+  }
+  return output
+}
 
 // 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: createArray, // change undefined to be the name of the function defined to create the range of numbers (the first todo)
+  b: shout // 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..74216aaf 100644
--- a/src/functions/creating-functions.js
+++ b/src/functions/creating-functions.js
@@ -7,7 +7,9 @@
 // 2      | 3
 //
 // TODO: write code below
-
+function addOne(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 +20,15 @@
 // Aiyana | Hi, Aiyana :)
 //
 // TODO: write code below
-
+function greeting(name) {
+  let toGreet = name[0].toUpperCase()
+  for (let i = 1; i < name.length; i++) {
+    toGreet += name[i]
+  }
+  return `Hi, ${toGreet} :)`
+}
 // 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: addOne, // change undefined to be the name of the function you defined to increment a number (the first TODO)
+  b: greeting // change undefined to be the name of the function you defined to say hi (the second TODO)
 }
diff --git a/src/loops/for-loop-and-arrays.js b/src/loops/for-loop-and-arrays.js
index 682995ec..db188d31 100644
--- a/src/loops/for-loop-and-arrays.js
+++ b/src/loops/for-loop-and-arrays.js
@@ -6,19 +6,33 @@ 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 (const num of nums) {
+  sum += num
+}
 
 // Use a for loop to populate doubledNums with every value from nums array doubled (i.e [2, 6, 24, etc...])
 const doubledNums = []
+for (const num of nums) {
+  doubledNums.push(num * 2)
+}
 
 // Use a for loop to set word equal to all the letters in the letters array
 word = ''
+for (const letter of letters) {
+  word += letter
+}
 
 // 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 = nums.length - 1; i >= 0; i--) {
+  numsReversed.push(nums[i])
+}
 
 // do not change below this line
 module.exports = {
diff --git a/src/loops/for-loop-basic.js b/src/loops/for-loop-basic.js
index 38a5c971..85166366 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 >= 0; 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..10035a95 100644
--- a/src/variables/assignment.js
+++ b/src/variables/assignment.js
@@ -1,11 +1,15 @@
 // do not edit this
-let firstNumber = 10
+let firstNumber = 20
 firstNumber = 0
 
 // TODO: Set the value of firstNumber below so the tests pass
 
+console.log("FIRST NUMBER: ", firstNumber)
+
+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..a141e472 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
+firstName = 'Jane'
+age = 35
 
 // do not edit below this line
 let firstNameExport = ''