diff --git a/advanced/arrow-function.js b/advanced/arrow-function.js
new file mode 100644
index 0000000..010d94a
--- /dev/null
+++ b/advanced/arrow-function.js
@@ -0,0 +1,26 @@
+const square = num => num * num
+
+console.log(square(5))
+
+const people = [{
+    name: 'Arun',
+    age: 32
+}, {
+    name: 'Adwiti',
+    age: 5
+}, {
+    name: 'Arav',
+    age: 1
+}, {
+    name: 'Pushpa',
+    age: 31
+}]
+
+const under30 = people.filter(person => person.age < 30)
+console.log(under30)
+
+//find a person with age 5
+//print the name of the person
+
+const equal5 = people.find(person => person.age ===5)
+console.log(equal5)
\ No newline at end of file
diff --git a/advanced/arrow-function2.js b/advanced/arrow-function2.js
new file mode 100644
index 0000000..d7ec6b2
--- /dev/null
+++ b/advanced/arrow-function2.js
@@ -0,0 +1,5 @@
+const add = function (a, b) {
+    return arguments[0] + arguments[1] + arguments[2]
+}
+
+console.log(add(10,20,30))
\ No newline at end of file
diff --git a/advanced/conditional.js b/advanced/conditional.js
new file mode 100644
index 0000000..b74d76e
--- /dev/null
+++ b/advanced/conditional.js
@@ -0,0 +1,35 @@
+let myAge = 27
+let message
+
+
+if (myAge >= 18) {
+    message = 'you can vote'
+} else {
+    message = 'you cannot vote'
+}
+console.log(message)
+
+//ternary operator
+myAge = 5
+
+message = myAge >= 18 ? 'You can vote' : 'You cannot vote'
+
+console.log(message)
+
+
+const showPage = () => {
+    return 'Showing the page'
+}
+
+const showErrorPage = () => {
+    return 'Showing the error page'
+}
+
+const newMessage = myAge >= 10 ? showPage() : showErrorPage()
+console.log(newMessage)
+
+
+const team = ['Tyler', 'Porter']
+
+const teamSize = team.length < 4 ? team.length : 'Too many people in the team'
+console.log(teamSize) 
\ No newline at end of file
diff --git a/advanced/grade-calc.js b/advanced/grade-calc.js
new file mode 100644
index 0000000..8081464
--- /dev/null
+++ b/advanced/grade-calc.js
@@ -0,0 +1,34 @@
+const gradleCalc = (score, totalScore) => {
+
+    if (typeof score !== 'number' || typeof totalScore !== 'number') {
+        throw Error('Please provide numbers')
+    }
+    const percentage = score / totalScore * 100
+
+    let grade = ''
+
+    if (percentage > 90) {
+        grade = 'A'
+    } else if (percentage >= 80) {
+        grade = 'B'
+    } else if (percentage >= 70) {
+        grade = 'C'
+    } else if (percentage >= 60) {
+        grade = 'D'
+    } else if (percentage >= 50) {
+        grade = 'E'
+    } else {
+        grade = 'F'
+    }
+
+    return `your got a grade of ${grade} with a percentage as ${percentage}`
+}
+
+try {
+    const result = gradleCalc(true, 1000)
+    console.log(result)
+} catch (e) {
+    console.log(e.message)
+}
+
+
diff --git a/advanced/truty-falsy.js b/advanced/truty-falsy.js
new file mode 100644
index 0000000..22f747a
--- /dev/null
+++ b/advanced/truty-falsy.js
@@ -0,0 +1,55 @@
+const products = [{ name: 'computer' }]
+const product = products[0]
+
+//Truthy value which resolves to true
+//Falsy - value the resolves to false
+//Falsy - false, 0, empty string, null , undefined, NaN
+
+
+//1. This will give true value, though the product is string
+if (product) {
+    console.log("Product found")
+} else {
+    console.log("Product not found")
+}
+
+console.log('-------false--------')
+if (false) {
+    console.log('this block will not be printed')
+} else {
+    console.log('else block will be printed')
+}
+console.log('-------0--------')
+if (0) {
+    console.log('this block will not be printed')
+} else {
+    console.log('else block will be printed')
+}
+
+console.log('--------Empty String-------')
+if ('') {
+    console.log('this block will not be printed')
+} else {
+    console.log('else block will be printed')
+}
+
+console.log('--------null-------')
+if (null) {
+    console.log('this block will not be printed')
+} else {
+    console.log('else block will be printed')
+}
+
+console.log('--------undefined-------')
+if (null) {
+    console.log('this block will not be printed')
+} else {
+    console.log('else block will be printed')
+}
+
+console.log('--------NaN-------')
+if (NaN) {
+    console.log('this block will not be printed')
+} else {
+    console.log('else block will be printed')
+}
diff --git a/advanced/try-catch.js b/advanced/try-catch.js
new file mode 100644
index 0000000..d538dc2
--- /dev/null
+++ b/advanced/try-catch.js
@@ -0,0 +1,18 @@
+const getTip = amount => {
+
+    if (typeof amount === 'number') {
+        return amount * .25
+    } else {
+        throw Error('Argument must be greater')
+    }
+
+}
+
+try {
+    console.log(getTip(10))
+} catch (e) {
+    console.log("Argument must be a number")
+}
+
+
+
diff --git a/advanced/type-coercion.js b/advanced/type-coercion.js
new file mode 100644
index 0000000..2245475
--- /dev/null
+++ b/advanced/type-coercion.js
@@ -0,0 +1,16 @@
+//Type coercion a String , a number , a boolean
+
+console.log('5' + 5) //o/p 55
+console.log('5' - 5) //o/p 0
+console.log(5 === 5) //true
+console.log(5 == 5) //true
+console.log('5' == 5) //true
+console.log('5' === 5) //false
+
+
+const type = typeof 123
+console.log(type) //number
+
+const value = true + 12
+console.log(typeof value) //number
+console.log(value) //13
diff --git a/notes/fn.js b/notes/fn.js
index 709f9f3..dfcce50 100644
--- a/notes/fn.js
+++ b/notes/fn.js
@@ -1,21 +1,24 @@
+'use strict'
+
 const divElement = document.querySelector('#addNotesDiv')
 
 
-const saveNotes = function (notes) {
+const saveNotes = (notes) => {
     localStorage.setItem('notes', JSON.stringify(notes))
 }
 
-const getNotes = function () {
+const getNotes = () => {
     const notes = localStorage.getItem('notes')
-    if (notes !== null) {
-        return JSON.parse(notes)
-    } else {
+    try{
+        return notes != null ? JSON.parse(notes) : []
+    }catch(e){
         return []
     }
+    
 }
 
-//sort notes by one of the three ways
-const sortNotes = function (notes, sortBy) {
+//sort notes by one of the three ways,
+const sortNotes = (notes, sortBy) => {
 
     if (sortBy === 'byEdited') {
         return notes.sort((a, b) => {
@@ -50,7 +53,7 @@ const sortNotes = function (notes, sortBy) {
         })
     }
 }
-const renderNotes = function (notes, filters) {
+const renderNotes = (notes, filters) => {
     if (filters !== undefined) {
         notes = sortNotes(notes, filters.sortBy)
         notes = notes.filter(note => {
@@ -74,7 +77,7 @@ const renderNotes = function (notes, filters) {
  * if you want to add a particular item in a paragraph
  * @param {a specific note which you want to display} note 
  */
-const generateDom = function (note) {
+const generateDom = (note) => {
     const para = document.createElement('p')
     para.textContent = note.text
     return para
@@ -84,7 +87,7 @@ const generateDom = function (note) {
  * if you want to add a button(x) with text next to it
  * @param {a specific note with a button before it} note 
  */
-const generateDomWithXButton = function (note) {
+const generateDomWithXButton = (note) => {
     const innerDivElement = document.createElement('div')
 
     const innerButtonElement = document.createElement('button')
@@ -101,7 +104,7 @@ const generateDomWithXButton = function (note) {
  * 
  * @param {add an event listener to the button} note 
  */
-const generateDomWithXButtonAndWithEventListener = function (note) {
+const generateDomWithXButtonAndWithEventListener = (note) => {
     //create a div element 
     const innerDivElement = document.createElement('div')
 
@@ -126,7 +129,7 @@ const generateDomWithXButtonAndWithEventListener = function (note) {
  * 
  * @param {add an event listener to button and link to next page} note 
  */
-const generateDomWithXElementAndLinkToNextPage = function (note) {
+const generateDomWithXElementAndLinkToNextPage = (note) => {
     //create a div element
     const divEl = document.createElement('div')
 
@@ -153,7 +156,7 @@ const generateDomWithXElementAndLinkToNextPage = function (note) {
  * 
  * @param {deletes a note} id 
  */
-const deleteNote = function (id) {
+const deleteNote = (id) => {
     const index = notes.findIndex(note => note.id === id)
     notes.splice(index, 1)
     saveNotes(notes)
@@ -164,6 +167,6 @@ const deleteNote = function (id) {
  * 
  * @param {get the time from the timestamp passed} timestamp 
  */
-const latestModifiedTime = function (timestamp) {
+const latestModifiedTime = (timestamp) => {
     return `last modified ${moment(timestamp).fromNow()}`
 }
diff --git a/oop/hangman.js b/oop/hangman.js
new file mode 100644
index 0000000..2f695a2
--- /dev/null
+++ b/oop/hangman.js
@@ -0,0 +1,12 @@
+const Hangman = function(word, numberOfGuess){
+    this.word = word
+    this.numberOfTries = numberOfGuess
+}
+
+const first = new Hangman('cat',2)
+const second = new Hangman('Peter',3)
+console.log(first)
+console.log(second)
+
+
+
diff --git a/oop/person.js b/oop/person.js
new file mode 100644
index 0000000..1193323
--- /dev/null
+++ b/oop/person.js
@@ -0,0 +1,27 @@
+const Person = function (firstName, lastName, age, likes = []) {
+    this.firstName = firstName
+    this.lastName = lastName
+    this.age = age
+    this.likes = likes
+}
+
+Person.prototype.getBio = function () {
+    let bio = `${this.firstName} is ${this.age} years old.`
+    this.likes.forEach(like => {
+        bio += ` ${this.firstName} likes ${like}`
+    })
+    return bio
+}
+
+Person.prototype.setName = function (fullName) {
+    const names = fullName.split(' ')
+    this.firstName = names[0]
+    this.lastName = names[1]
+}
+
+const me = new Person('Arun', 'Singh', 10, ['Reading','Playing'])
+me.setName('Alex Singh')
+console.log(me.getBio())
+
+const wife = new Person('Pushpa', 'Yadav', 5)
+console.log(wife.getBio())
\ No newline at end of file