diff --git a/src/conditional-flow/boolean-conditions.js b/src/conditional-flow/boolean-conditions.js
index 70b623d4..bac24e2b 100644
--- a/src/conditional-flow/boolean-conditions.js
+++ b/src/conditional-flow/boolean-conditions.js
@@ -1,10 +1,18 @@
 // This function should accept a boolean value and return the string
 // "Well done, you passed!" if the value is true, or "Sorry, try again"
 // if the value is false.
+
 function getResult (didPass) {
+  let result="";
 
-  // TODO: write code in this function body to pass the tests
+  if(didPass){
+   result = "Well done, you passed!";
+  }else{
+   result = "Sorry, try again";
+  }
 
+  // TODO: write code in this function body to pass the tests
+return result;
 }
 
 module.exports = {
diff --git a/src/conditional-flow/multiple-conditions.js b/src/conditional-flow/multiple-conditions.js
index 80420abf..32311dac 100644
--- a/src/conditional-flow/multiple-conditions.js
+++ b/src/conditional-flow/multiple-conditions.js
@@ -1,19 +1,26 @@
 // 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) {
+  let result = false
+  if (num >= lower && num <= upper) {
+    result = true
+  }
+  return result
 
   // TODO: write code in this function body to pass the tests
-
 }
 
 // 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) {
+  let result = false
+  if (val1 == 'Hello' || val1 == 'Goodbye') {
+    result = true
+  }
+  return result
   // TODO: write code in this function body to pass the tests
-
 }
 
 // This function should return a string that describes the provided age value. The
@@ -28,8 +35,24 @@ function isHelloOrGoodbye (val1) {
 // 5-12   | Child
 // 13-19  | Teenager
 // 20+    | Adult
-function getAgeDescription (age) {
-
+function getAgeDescription(age) {
+  let ageString ="";
+  if(age ===0){
+    ageString="Baby";
+  }else if(age>=1 && age<=4){
+    ageString="Toddler";
+  }
+  else if(age>=5 && age<=12){
+    ageString="Child";
+  }
+  else if(age>=13 && age<=19){
+    ageString="Teenager";
+  }
+  else if(age>=20){
+    ageString="Adult";
+  }
+  return ageString;
+  
   // TODO: write code in this function body to pass the tests
 }
 
diff --git a/src/conditional-flow/numeric-conditions.js b/src/conditional-flow/numeric-conditions.js
index 0f6656a5..5c1f796c 100644
--- a/src/conditional-flow/numeric-conditions.js
+++ b/src/conditional-flow/numeric-conditions.js
@@ -1,24 +1,39 @@
 // TODO: Implement the functions below to make the tests pass
 
 // This function should return true if there are no elements in the array, false otherwise
-function isArrayEmpty (array) {
-
+function isArrayEmpty(array) {
+  let result;
+  if (array == null||array.length == 0) {
+    result=true;
+
+  }else{
+    result = false;
+  }
+  return result;
+  
   // TODO: write code in this function body to pass the tests
-
 }
 
 // This function should return true if num1 is greater than num2, false otherwise
-function isGreaterThan (num1, num2) {
-
+function isGreaterThan(num1, num2) {
+  if(num1 > num2){
+    return true;
+  }else{
+    return false;
+  }
   // TODO: write code in this function body to pass the tests
-
 }
 
 // This function should return the lowest number in the passed array
-function findLowest (nums) {
-
+function findLowest(nums) {
+  let lowestNum = nums[0];
+  for (var i = 0; i <= nums.length; i++){
+    if(lowestNum>nums[i]){
+      lowestNum=nums[i];
+    }
+  }
+  return lowestNum;
   // TODO: write code in this function body to pass the tests
-
 }
 
 module.exports = {
diff --git a/src/conditional-flow/string-conditions.js b/src/conditional-flow/string-conditions.js
index d91bfaf0..a8a4687f 100644
--- a/src/conditional-flow/string-conditions.js
+++ b/src/conditional-flow/string-conditions.js
@@ -1,45 +1,87 @@
 // This function should return true if the passed string is equal to "Hello"
-function isHello (val1) {
-
+function isHello(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 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) {
-
-  // TODO: write code in this function body to pass the tests
-
+function hasOddNumberVowels(val1) {
+  let vowels = ['a', 'A', 'e', 'E', 'i', 'I', 'o', 'O', 'u', 'U']
+  let vowelsNum = 0
+  let result
+
+  for (let i = 0; i < val1.length; i++) {
+    for (let j = 0; j < vowels.length; j++) {
+      if (val1[i] == vowels[j]) {
+        vowelsNum = vowelsNum + 1
+      }
+    }
+  }
+
+  if (vowelsNum % 2 == 0) {
+    return (result = false)
+  } else {
+    return (result = true)
+  }
 }
+// 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) {
-  // TODO: write code in this function body to pass the tests
+function getMiddleLetter(val1) {
+  let val2 = Array.from(val1)
+
+  let valStr = ''
 
+  let valNum = val1.length
+  let halfStr = valNum / 2
+  halfStr = halfStr.toFixed(0)
+  //Even String
+  if (valNum % 2 == 0) {
+    valStr = val2[halfStr - 1] + val2[halfStr]
+    console.log(valStr + ' ' + halfStr)
+  } //Odd String
+  else if (valNum % 2 != 0) {
+    valStr = val2[halfStr - 1]
+  }
+
+  return valStr
+  // TODO: write code in this function body to pass the tests
 }
 
 // This function should return the name of the season for the provided
-// month name. For example, "January" should return "Winter". If the provided
+// month name.
+//For example, "January" should return "Winter". If the provided
 // value is not a valid month, an empty string ("") should be returned. Use
 // the below ranges for each season:
 //
@@ -47,9 +89,25 @@ 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 season;
+
+  if(monthName == 'March' || monthName == 'April' || monthName == 'May') {
+    season = 'Spring';
+  }else if(monthName =='June' || monthName == 'July' || monthName == 'August'){
+    season = 'Summer';
+  }else if(monthName == 'September' || monthName == 'October' || monthName =='November'){
+    season='Autumn';
+  }else if(monthName == 'December' || monthName=='January'|| monthName=='February'){
+    season='Winter';
+  }else{
+      season="";
+    
+  
+  }
+  return season;
 }
 
 module.exports = {
diff --git a/src/data-types/arrays/accessing-elements.js b/src/data-types/arrays/accessing-elements.js
index 374a19bb..257df20b 100644
--- a/src/data-types/arrays/accessing-elements.js
+++ b/src/data-types/arrays/accessing-elements.js
@@ -1,19 +1,19 @@
 // do not edit this section
-const cities = ['London', 'Shanghai', 'New York', 'Delhi', 'Kuala Lumpur']
+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..8037469b 100644
--- a/src/data-types/arrays/adding-removing-elements.js
+++ b/src/data-types/arrays/adding-removing-elements.js
@@ -10,25 +10,27 @@ 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.splice(0,1);
 
 // Use an array method to remove the last item from keys
-keys
+keys.splice(keys.length-1,1);
 
 // 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[fruits.length-1];
+fruits.splice(fruits.length-1,1);
+
 
 // Do not edit this exported object
 module.exports = {
diff --git a/src/data-types/numbers.js b/src/data-types/numbers.js
index 01dd70de..6f298f9d 100644
--- a/src/data-types/numbers.js
+++ b/src/data-types/numbers.js
@@ -6,22 +6,23 @@ 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..3188877c 100644
--- a/src/data-types/objects/creating-objects.js
+++ b/src/data-types/objects/creating-objects.js
@@ -1,7 +1,21 @@
 // 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..833d0159 100644
--- a/src/data-types/objects/object-keys.js
+++ b/src/data-types/objects/object-keys.js
@@ -1,26 +1,28 @@
 // do not edit this section
+const isbn13 = '978-0132350884'
 const book = {
   name: 'Clean Code',
   author: 'Robert C. Martin',
-  category: 'Cooking',
+  category: 'Programming',
   isbn: {
     isbn10: '9780132350884',
-    asin: '0132350882'
+    isbn13:isbn13
   },
-  publisher: 'Prentice Hall',
-  dimensions: '10x12x2'
+  pages:464,
+  
+  publisher: 'Prentice Hall'
 }
 
-const isbn13 = '978-0132350884'
+
 
 // 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
 
 // Set this to the book name
-const name = ''
+const name = book.name;
 
 // Set this to the isbn 10 value
-const isbn10 = ''
+const isbn10 =book.isbn.isbn10;
 
 // 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..3366d119 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',
+      price: 0.75,
+      quantity:4
     }
   ],
   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..f62c86dd 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.charAt(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..68d202fc 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 = numOne+numTwo;// 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..915cb3d7 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 = ''
+let hello = sayHello();
 
 // Set this variable variable to 'Hello Jane' calling the sayHelloTo function
-const helloToJane = ''
+let helloToJane = sayHelloTo('Jane');
 
 // Set this variable to 'Hello Bob! Hello Bob! Hello Bob!' calling the sayHelloManyTimes function
-const helloToBob3Times = ''
+let 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..ced62545 100644
--- a/src/functions/creating-functions-multiple-args.js
+++ b/src/functions/creating-functions-multiple-args.js
@@ -8,6 +8,19 @@
 // 10, 13       | [10, 11, 12, 13]
 // -1, 1        | [-1, 0, 1]
 //
+function lowerAndUpper(lower, upper){
+  console.log(lower, upper);
+  let limitArray=[];
+  let count = 0;
+
+  for (let i = lower; i <= upper; i++) {
+    limitArray[count] = i;
+    count = count + 1;
+    console.log(limitArray[count]);
+  }
+  return limitArray;
+}
+
 // TODO: write code below
 
 // define a function that takes two arguments: a string and a number.
@@ -21,9 +34,17 @@
 // error, 10    | ERROR!!!!!!!!!!
 //
 // TODO: write code below
+function concatMyString(str,number){
+  let newStr = str.toUpperCase();
+  for(let i = 0; i < number;i++){
+    newStr = newStr.concat("!");
+  }
+  return newStr;
+
+}
 
 // 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: lowerAndUpper, // change undefined to be the name of the function defined to create the range of numbers (the first todo)
+  b: concatMyString // 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..f75dad99 100644
--- a/src/functions/creating-functions.js
+++ b/src/functions/creating-functions.js
@@ -7,6 +7,9 @@
 // 2      | 3
 //
 // TODO: write code below
+function incrementNumber(number){
+  return number + 1;
+}
 
 // Define a function that takes any person's name and returns it with a smiley :)!
 // Remember to make the name capitalized!
@@ -17,10 +20,18 @@
 // edward | Hi, Edward :)
 // Aiyana | Hi, Aiyana :)
 //
+function helloEveryone(name){
+  let newChar =Array.from(name);
+  let firstChar= newChar[0].toUpperCase();
+  newChar[0] = firstChar;
+  let newStr = newChar.join('');
+
+  return "Hi, " + newStr+" :)";
+}
 // TODO: write code below
 
 // 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: incrementNumber, // change undefined to be the name of the function you defined to increment a number (the first TODO)
+  b: helloEveryone // 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..8ca0d239 100644
--- a/src/loops/for-loop-and-arrays.js
+++ b/src/loops/for-loop-and-arrays.js
@@ -5,20 +5,52 @@ 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
+// Use a for loop to set the sum variable to{} the sum of all the values in nums
+
+  for (let i = 0; i < nums.length; i++) {
+    sum = 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 = []
+  let doubledNums=[]
+  for (let i = 0; i < nums.length; i++) {
+    doubledNums[i] = nums[i]*2;
+  }
+
 
 // Use a for loop to set word equal to all the letters in the letters array
-word = ''
+word = '';
+let newWord=[];
+for (let i = 0; i < letters.length; i++) {
+  newWord[i] = letters[i];
+}
+word = newWord.join('');
 
 // Use a for loop to populate everySecondNum with every second number from the nums array
-const everySecondNum = []
+const everySecondNum = [];
+let count1=0;
+
+for (let i = 0; i < nums.length; i++){
+ 
+ if(i%2 != 0){
+  everySecondNum[count1] =nums[i];
+  count1++;
+ }
 
+}
 // Use a for loop to populate numsReversed with the numbers from nums in reverse order
-const numsReversed = []
+const numsReversed = [];
+let count = 0;
+console.log(nums.length);
+for (let i = nums.length; i > 0; i=i-1){
+  numsReversed[count]=nums[i-1];
+  console.log(numsReversed[count]);
+  count=count+1;
+
+}
+
+
 
 // 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..5a4b755e 100644
--- a/src/loops/for-loop-basic.js
+++ b/src/loops/for-loop-basic.js
@@ -4,12 +4,31 @@ 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[i]=i;
+}
 
 // TODO: Write a for loop that adds the numbers 5 to 10 to the numsFiveToTen array
+let five=5;
+for (let i =0; i <6; i++){
+  numsFiveToTen[i]=five++;
+}
 
 // TODO: Write a for loop that adds all the even numbers between 0 and 6 (0, 2, 4, 6) to evenNums
+let even=0;
+for (let i =0; i <4; i++){
+  evenNums[i]=even;
+  even=even+2;
+}
 
 // TODO: Write a for loop that adds the numbers 3 to 0 (in that order) to the countdown array
+let count=3;
+for (let i =0; i <4; i++){
+
+ countdown[i]=count;
+ count--;
+
+}
 
 // do not change below this line
 module.exports = {
diff --git a/src/variables/assignment.js b/src/variables/assignment.js
index 98f2e31c..aa01d00a 100644
--- a/src/variables/assignment.js
+++ b/src/variables/assignment.js
@@ -3,9 +3,10 @@ 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..3e857bed 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';
+let age=35;
 
 // do not edit below this line
 let firstNameExport = ''