diff --git a/Nguyen-Kevin-JS-Leet-Practice/longestSubstring.js b/Nguyen-Kevin-JS-Leet-Practice/longestSubstring.js
new file mode 100644
index 0000000..25e1840
--- /dev/null
+++ b/Nguyen-Kevin-JS-Leet-Practice/longestSubstring.js
@@ -0,0 +1,17 @@
+function lengthOfLongestSubstring(s) {
+    let windowCharsMap = {};
+    let windowStart = 0;
+    let maxLength = 0;
+
+    for (let i =0; i < s.length; i++) {
+        const endChar = s[i];
+
+        if(windowCharsMap[endChar] >= windowStart) {
+            windowStart = windowCharsMap[endChar] + 1;
+        }
+
+        windowCharsMap[endChar] = i;
+        maxLength = Math.max(maxLength, i - windowStart + 1);
+    }
+    return maxLength;
+}
\ No newline at end of file
diff --git a/Nguyen-Kevin-JS-Leet-Practice/palindrome.js b/Nguyen-Kevin-JS-Leet-Practice/palindrome.js
new file mode 100644
index 0000000..a0f1fb3
--- /dev/null
+++ b/Nguyen-Kevin-JS-Leet-Practice/palindrome.js
@@ -0,0 +1,17 @@
+
+function isParlindrome(s){
+    s =s.toLowerCase().replace(/[^\w]/g, "");
+
+    let left = 0;
+    let right = s.length -1;
+
+    while(left < right) {
+        if (s[left] !== s[right]){
+            return false;
+        }
+        left++;
+        right--;
+    }
+    return true;
+}
+
diff --git a/Traub-Eric-JS-Practice/10_use_strict.js b/Traub-Eric-JS-Practice/10_use_strict.js
new file mode 100644
index 0000000..d5024d5
--- /dev/null
+++ b/Traub-Eric-JS-Practice/10_use_strict.js
@@ -0,0 +1,44 @@
+// example 1
+
+/* require let, var, const 
+   for variable declaration
+*/
+
+'use strict';
+
+city = 'London'; 
+console.log(city);
+ 
+ 
+ 
+ 
+// example 2
+
+/*
+parameters must be unique
+
+*/
+
+'use strict';
+
+function myFunc(a, a, b) {
+    console.log(a, a, b);
+}
+myFunc(1, 2, 3);
+ 
+ 
+ 
+ 
+// example 3
+ 
+/*
+errors thrown for attempts to delete
+native definitions
+*/
+
+'use strict';
+
+delete Object.prototype;
+
+
+// use strict: fail FAST & fail LOUDLY
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/11_curry_function.js b/Traub-Eric-JS-Practice/11_curry_function.js
new file mode 100644
index 0000000..4f2a950
--- /dev/null
+++ b/Traub-Eric-JS-Practice/11_curry_function.js
@@ -0,0 +1,32 @@
+// tab 1
+ 
+// function getProduct(num1, num2) {
+//   return num1 * num2;
+// }
+ 
+function getProduct(num1) {
+  return function(num2) {
+    return num1 * num2;
+  };
+}
+ 
+getProduct(10)(20);
+ 
+ 
+ 
+ 
+// tab 2
+ 
+// function getTravelTime(distance, speed) {
+//   return distance / speed;
+// }
+ 
+function getTravelTime(distance) {
+  return function(speed) {
+    return distance / speed;
+  };
+}
+ 
+const travelTimeBosNyc = getTravelTime(400);
+const travelTimeMiamiAtlanta = getTravelTime(600);
+console.log(travelTimeBosNyc(100));
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/12_counter_function.js b/Traub-Eric-JS-Practice/12_counter_function.js
new file mode 100644
index 0000000..c672cd3
--- /dev/null
+++ b/Traub-Eric-JS-Practice/12_counter_function.js
@@ -0,0 +1,20 @@
+function myFunc() {
+    let count = 0;
+    
+    return function() {
+      count++;
+      return count;
+    };
+  }
+   
+  console.log(myFunc());
+   
+  const instanceOne = myFunc();
+  const instanceTwo = myFunc();
+   
+  console.log('instanceOne: ', instanceOne());
+  console.log('instanceOne: ', instanceOne());
+  console.log('instanceOne: ', instanceOne());
+  console.log('instanceTwo: ', instanceTwo());
+  console.log('instanceTwo: ', instanceTwo());
+  console.log('instanceOne: ', instanceOne());
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/13_logging_x_and_y.js b/Traub-Eric-JS-Practice/13_logging_x_and_y.js
new file mode 100644
index 0000000..fa0764b
--- /dev/null
+++ b/Traub-Eric-JS-Practice/13_logging_x_and_y.js
@@ -0,0 +1,8 @@
+"use strict";
+ 
+(function() {
+  var x = y = 200;
+})();
+ 
+console.log('y: ', y);
+console.log('x: ', x);
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/14_call_and_apply.js b/Traub-Eric-JS-Practice/14_call_and_apply.js
new file mode 100644
index 0000000..2db210d
--- /dev/null
+++ b/Traub-Eric-JS-Practice/14_call_and_apply.js
@@ -0,0 +1,18 @@
+const car1 = {
+  brand: 'Porsche',
+  getCarDescription: function(cost, year, color) {
+    console.log(`This car is a ${this.brand}. The price is $${cost}. The year is ${year}. The color is ${color}.\n`);
+  }
+};
+ 
+const car2 = {
+  brand: 'Lamborghini'
+};
+ 
+const car3 = {
+  brand: 'Ford'
+};
+ 
+car1.getCarDescription(80000, 2010, 'blue');
+car1.getCarDescription.call(car2, 200000, 2013, 'yellow');
+car1.getCarDescription.apply(car3, [35000, 2012, 'black']);
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/15_determine_list2.js b/Traub-Eric-JS-Practice/15_determine_list2.js
new file mode 100644
index 0000000..dbe3a31
--- /dev/null
+++ b/Traub-Eric-JS-Practice/15_determine_list2.js
@@ -0,0 +1,8 @@
+const list1 = [1, 2, 3, 4, 5];
+const list2 = list1.slice();
+// const list2 = list1.concat([]);
+ 
+list1.push(6, 7, 8);
+ 
+console.log('List 1: ', list1);
+console.log('List 2: ', list2);
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/16_singly_doubly_invoked_functions.js b/Traub-Eric-JS-Practice/16_singly_doubly_invoked_functions.js
new file mode 100644
index 0000000..901eeaa
--- /dev/null
+++ b/Traub-Eric-JS-Practice/16_singly_doubly_invoked_functions.js
@@ -0,0 +1,17 @@
+function getTotal() {
+    var args = Array.prototype.slice.call(arguments);
+    
+    if (args.length === 2) {
+      return args[0] + args[1];
+    }
+    else if (args.length === 1) {
+      return function(num2) {
+        return args[0] + num2;
+      };
+    }
+  }
+   
+  console.log(getTotal(10, 20));
+  console.log(getTotal(5, 40));
+  console.log(getTotal(3)(30));
+  console.log(getTotal(8)(12));
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/17_json_data.js b/Traub-Eric-JS-Practice/17_json_data.js
new file mode 100644
index 0000000..722ed53
--- /dev/null
+++ b/Traub-Eric-JS-Practice/17_json_data.js
@@ -0,0 +1,17 @@
+// TASK:
+// 1. Describe what JSON format is.
+// 2. Delete the data types not permitted in JSON.
+// 3. Replace placeholder-text with the corresponding data type,
+//    properly formatted as JSON.
+ 
+const myJsonObj = {
+    "myString": "hello world",
+    "myNumber": 12345.6789,
+    "myNull": null,
+    "myBoolean": true,
+    "myArray": [20, 30, "orange"],
+    "myObject": {
+      "name": "Sam",
+      "age": 30
+    }
+  };
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/18_order_logged_out.js b/Traub-Eric-JS-Practice/18_order_logged_out.js
new file mode 100644
index 0000000..2666ce6
--- /dev/null
+++ b/Traub-Eric-JS-Practice/18_order_logged_out.js
@@ -0,0 +1,8 @@
+function logNumbers() {
+  console.log(1); 
+  setTimeout(function(){console.log(2)}, 1000); 
+  setTimeout(function(){console.log(3)}, 0); 
+  console.log(4);
+}
+ 
+logNumbers();
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/19_creating_objects.js b/Traub-Eric-JS-Practice/19_creating_objects.js
new file mode 100644
index 0000000..ded5ef3
--- /dev/null
+++ b/Traub-Eric-JS-Practice/19_creating_objects.js
@@ -0,0 +1,38 @@
+// object literal syntax
+const myBoat = {
+    length: 24,
+    maxSpeed: 45,
+    passengers: 14,
+    getLength: function() {
+      return this.length;
+    }
+  }; 
+   
+   
+  // new keyword & Object constructor
+  const student = new Object();
+   
+  student.grade = 12;
+  student.gradePointAverage = 3.7;
+  student.classes = ["English", "Algebra", "Chemistry"];
+  student.getClasses = function() {
+    return this.classes;
+  };
+   
+   
+  // constructor function 
+  function Car(color, brand, year) {
+    this.color = color;
+    this.brand = brand;
+    this.year = year;
+  }
+   
+  Car.prototype.getColor = function() {
+    return this.color;
+  };
+   
+  const carlysCar = new Car('blue', 'ferarri', 2015);
+  const jimsCar = new Car('red', 'tesla', 2014);
+   
+  console.log(carlysCar.getColor());
+  console.log(jimsCar.getColor());
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/1_tripleAdd.js b/Traub-Eric-JS-Practice/1_tripleAdd.js
new file mode 100644
index 0000000..73920b1
--- /dev/null
+++ b/Traub-Eric-JS-Practice/1_tripleAdd.js
@@ -0,0 +1,9 @@
+tripleAdd(10)(20)(30); // 60
+
+function tripleAdd(num1) {
+    return function(num2) {
+        return function(num3) {
+            return num1 + num2 + num3;
+        }
+    }
+}
diff --git a/Traub-Eric-JS-Practice/20_typeof_data_types.js b/Traub-Eric-JS-Practice/20_typeof_data_types.js
new file mode 100644
index 0000000..8fd20c6
--- /dev/null
+++ b/Traub-Eric-JS-Practice/20_typeof_data_types.js
@@ -0,0 +1,6 @@
+console.log(typeof null);
+console.log(typeof undefined);
+console.log(typeof {});
+console.log(typeof []);
+console.log(Array.isArray([]));
+console.log([] instanceof Array);
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/2_iife.js b/Traub-Eric-JS-Practice/2_iife.js
new file mode 100644
index 0000000..356033e
--- /dev/null
+++ b/Traub-Eric-JS-Practice/2_iife.js
@@ -0,0 +1,7 @@
+// immediately invoked function
+
+(function doubleNumber(num){
+    return num * 2;
+})(10);
+
+doubleNumber(5);
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/3_button_5.js b/Traub-Eric-JS-Practice/3_button_5.js
new file mode 100644
index 0000000..4904551
--- /dev/null
+++ b/Traub-Eric-JS-Practice/3_button_5.js
@@ -0,0 +1,56 @@
+// function createButtons() {
+//     for (var i = 1; i <= 5; i++) {
+//       var body = document.getElementsByTagName("BODY")[0];
+//       var button = document.createElement("BUTTON");
+//       button.innerHTML = 'Button ' + i;
+//       button.onclick = function() {
+//            alert('This is button ' + i);
+//       }
+//       body.appendChild(button);
+//     }
+//  }
+  
+//  createButtons();
+
+  // Solution 2:
+
+function createButtons() {
+    for (var i = 1; i <= 5; i++) {
+      var body = document.getElementsByTagName("BODY")[0];
+      var button = document.createElement("BUTTON");
+      button.innerHTML = 'Button ' + i;
+ //      (function(num) {
+ //      button.onclick = function() {
+ //           alert('This is button ' + num);
+ //      };
+ //      })(i)
+      addClickFunctionality(button, i);
+      body.appendChild(button);
+    }
+ }
+  
+ createButtons();
+ 
+ 
+ function addClickFunctionality(button, num) {
+     button.onclick = function() {
+         alert('This is button ' + num);
+     }
+  }
+
+  // Solution 3:
+  //   let is block scoped instead of function scoped
+ 
+function createButtons() {
+    for (let i = 1; i <= 5; i++) {
+      var body = document.getElementsByTagName("BODY")[0];
+      var button = document.createElement("BUTTON");
+      button.innerHTML = 'Button ' + i;
+      button.onclick = function() {
+           alert('This is button ' + i);
+      }
+      body.appendChild(button);
+    }
+ }
+  
+ createButtons();
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/4_closure.js b/Traub-Eric-JS-Practice/4_closure.js
new file mode 100644
index 0000000..e69de29
diff --git a/Traub-Eric-JS-Practice/5_this.js b/Traub-Eric-JS-Practice/5_this.js
new file mode 100644
index 0000000..e69de29
diff --git a/Traub-Eric-JS-Practice/7_self.js b/Traub-Eric-JS-Practice/7_self.js
new file mode 100644
index 0000000..8d4966c
--- /dev/null
+++ b/Traub-Eric-JS-Practice/7_self.js
@@ -0,0 +1,22 @@
+var myCar = {
+    color: "Blue",
+    logColor: function() {
+        var self = this;
+        console.log("In logColor - this.color: " + this.color);
+        console.log("In logColor - self.color: " + self.color);
+        (function() {
+            console.log("In IIFE - this.color: " + this.color);
+            console.log("In IIFE - self.color: " + self.color);
+        })();
+    }
+};
+ 
+myCar.logColor();
+
+
+/*
+blue
+blue
+undefined
+blue
+*/
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/8_equals_vs_strict.js b/Traub-Eric-JS-Practice/8_equals_vs_strict.js
new file mode 100644
index 0000000..3c1c954
--- /dev/null
+++ b/Traub-Eric-JS-Practice/8_equals_vs_strict.js
@@ -0,0 +1,15 @@
+console.log(7 == '7');  // true
+ 
+console.log(7 === '7');  // false
+
+
+/*
+==
+
+num == str // string converted to num
+
+boolean == non-boolean // non-boolean converted to boolean
+
+object == primitive // object converted to primitive
+
+*/
\ No newline at end of file
diff --git a/Traub-Eric-JS-Practice/9_log_numer.js b/Traub-Eric-JS-Practice/9_log_numer.js
new file mode 100644
index 0000000..016e719
--- /dev/null
+++ b/Traub-Eric-JS-Practice/9_log_numer.js
@@ -0,0 +1,8 @@
+var num = 50;
+ 
+function logNumber() {
+    console.log(num);
+    var num = 100;
+}
+ 
+logNumber();
\ No newline at end of file
diff --git a/Traversy_Brad_Modern_JS/index.html b/Traversy_Brad_Modern_JS/index.html
new file mode 100644
index 0000000..f15b337
--- /dev/null
+++ b/Traversy_Brad_Modern_JS/index.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=<device-width>, initial-scale=1.0">
+    <title>Document</title>
+</head>
+<body>
+    <h1>Objects</h1>
+    <script src = "script.js"></script>
+    <button>Click</button>
+</body>
+</html>
\ No newline at end of file
diff --git a/Traversy_Brad_Modern_JS/script.js b/Traversy_Brad_Modern_JS/script.js
new file mode 100644
index 0000000..5b0e602
--- /dev/null
+++ b/Traversy_Brad_Modern_JS/script.js
@@ -0,0 +1,618 @@
+class Wallet {
+    #balance = 0;
+    #transactions = [];
+
+
+    constructor() {
+        this._balance = 0;
+        this._transactions = [];
+    }
+
+    deposit(amount) {
+        this.#processDeposit(amount);
+        this.#balance += amount;
+    }
+
+    withdraw(amount) {
+        if(amount >= this.#balance){
+            console.log('Not enough funds');
+            return;
+        }
+        this.#processWithdraw(amount);
+        this.#balance -= amount;
+    }
+
+    #processDeposit(amount) {
+        console.log(`Depositng ${amount}`);
+
+        this._transactions.push({
+            type: 'deposit',
+            amount 
+        })
+    }
+
+    #processWithdraw(amount) {
+        console.log(`Withdrawing ${amount}`);
+
+        this._transactions.push({
+            type: 'withdraw',
+            amount 
+        })
+    }
+
+    get balance() {
+        return this.#balance;
+    }
+
+    get transactions() {
+        return this.#transactions;
+    }
+}
+
+const wallet = new Wallet();
+wallet.deposit(300);
+wallet.withdraw(50);
+// console.log(wallet._balance);
+// console.log(wallet.balance);
+// console.log(wallet.transactions);
+
+// console.log(wallet.#balance);
+console.log(wallet.transactions);
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+// // Constructor function
+// function Person (firstName, lastName){
+//     this._firstName = firstName;
+//     this._lastName = lastName;
+
+//     Object.defineProperty(this, 'firstName', {
+//         get: function () {
+//             return this.captializeFirst(this._firstName);
+//         },
+//         set: function (value) {
+//             this._firstName = value;
+//         }
+//     });
+
+//     Object.defineProperty(this, 'lastName', {
+//         get: function () {
+//             return this.captializeFirst(this._lastName);
+//         },
+//         set: function (value) {
+//             this._lasstName = value;
+//         }
+//     });
+
+//     Object.defineProperty(this, 'fullName', {
+//         get: function () {
+//             return this.firstName + " " + this.lastName;
+//         },
+//     });
+
+// }
+
+// Person.prototype.captializeFirst = function(value) {
+//     return value.charAt(0).toUpperCase() + value.slice(1);
+// };
+
+// //Object literal
+// const PersonObj = {
+//     _firstName: 'jane',
+//     _lastName: 'doe',
+
+//     get firstName() {
+//         return Person.prototype.captializeFirst(this._firstName)
+//     },
+
+//     set firstName(value) {
+//         this._firstName = value;
+//     },
+
+//     get lastName() {
+//         return Person.prototype.captializeFirst(this._lastName);
+//     },
+
+//     set lastName(value) {
+//         this._lastName = value;
+//     },
+   
+//     get fullName() {
+//         return this._firstName +  " " + this.lastName;
+//     }
+// }
+
+// const person1 = new Person('john', 'doe');
+// console.log(person1.firstName);
+// console.log(person1.lastName);
+// console.log(person1.fullName);
+
+// const person2 = new Person('jane', 'dough');
+// console.log(person2.firstName);
+// console.log(person2.lastName);
+// console.log(person2.fullName);
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+// class Person {
+//     constructor (firstName, lastName) {
+//         this._firstName = firstName;
+//         this._lastName = lastName;
+//     }
+
+//     get firstName() {
+//         // return this._firstName.charAt(0).toUpperCase() + this._firstName.slice(1);
+//         return this.captializeFirst(this._firstName);
+//     }
+
+//     set firstName(value) {
+//         this._firstName = value.charAt(0).toUpperCase() + value.slice(1);
+//     }
+
+//     get lastName() {
+//         // return this._firstName.charAt(0).toUpperCase() + this._firstName.slice(1);
+//         return this.captializeFirst(this._lastName);
+//     }
+
+//     set lastName(value) {
+//         this._lastName = value.charAt(0).toUpperCase() + value.slice(1);
+//     }
+
+//     captializeFirst(value) {
+//         return value.charAt(0).toUpperCase() + value.slice(1);
+//     }
+
+//     get fullName() {
+//         return `${this.firstName} ${this._lastName}`;
+//     }
+// }
+
+
+// const person1 = new Person('john', 'doe');
+// console.log(person1.firstName);
+// console.log(person1.lastName);
+
+
+// person1.firstName = 'joseph';
+// person1.lastName = 'smith';
+// console.log(person1);
+// console.log(person1.fullName);
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+// class App {
+//     constructor() {
+//         this.serverName = 'localhost';
+
+//         document.querySelector('button').addEventListener('Click', this.getServerName.bind(this));
+//     }
+
+//     getServerName() {
+//         console.log(this.serverName);
+//     }
+// }
+
+// const app = new App();
+// // app.getServerName();
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+// class Rectangle {
+//     constructor(name, height, width) {
+//         this.name = name;
+//         this.height = height;
+//         this.width = width;
+//     }
+
+//     area() {
+//         return this.height * this.width;
+//     }
+
+//     static getClass() {
+//         return 'Rectangle';
+//     }
+// }
+
+
+// const rect = new Rectangle('Rect', 10, 10);
+// console.log(rect.area());
+// console.log(Rectangle.getClass());
+
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+
+
+// // Parent class
+// class Shape {
+//     constructor(name) {
+//         this.name = name;
+//     }
+
+//     logName() {
+//         console.log('Shape name: ', this.name);
+//     }
+// }
+
+// // Sub Class
+// class Rectangle extends Shape {
+//     constructor(name, width, height) {
+//         super(name);
+
+//         this.height = height;
+//         this.width = width;
+//     }
+// }
+
+// class Circle extends Shape {
+//     constructor(name, radius) {
+//         super(name);
+
+//         this.readius = radius;
+//     }
+
+//     logName() {
+//         console.log('Circle Name: ' + this.name)
+//     }
+// }
+
+
+
+
+// const rect = new Rectangle('Rect 1', 20, 20);
+// console.log(rect);
+// rect.logName();
+
+// const cir = new Circle('Cir 1', 30);
+// cir.logName();
+
+// console.log(rect instanceof Rectangle);
+// console.log(rect instanceof Shape);
+
+
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+
+
+// function Player(name) {
+//     this.name = name;
+//     this.lvl = 1;
+//     this.points = 0;
+// }
+
+// Player.prototype.gainXp = function (xp) {
+//     this.points += xp;
+
+//     if(this.points >= 10) 
+//     {   this.lvl++;
+//         this.points -= 10;
+//     }
+// }
+
+// Player.prototype.describe = function(){
+//     return `${this.name} is level ${this.lvl} with ${this.points}
+//     experience points`;
+// }
+
+// const player1 = new Player('Bob');
+// const player2 = new Player('Alice');
+
+// player1.gainXp(4);
+// player2.gainXp(7);
+// player1.gainXp(5);
+// player2.gainXp(1);
+// player1.gainXp(7);
+// player2.gainXp(9);
+// player1.gainXp(5);
+// player2.gainXp(2);
+
+// console.log(player1.describe());
+// console.log(player2.describe());
+
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+
+
+// function Rectangle(name, width, height) {
+//     this.name = name;
+//     this.width = width;
+//     this.height = height;
+//     this.area = function() {
+//         return this.width * this.height;
+//     };
+// }
+
+// const rect = new Rectangle('React', 10, 10);
+// console.log(rect);
+
+// Rectangle.prototype.area = function () {
+//     return (this.width * this.height);
+// }
+
+// const rectanglePrototypes = {
+//     area: function () {
+//         return this.width * this.height
+//     },
+//     perimeter: function () {
+//         return 2 * (this.width + this.height)
+//     },
+//     isSquare: function () {
+//         return (this.height === this.width)
+//     }
+// }
+
+
+// function createRectangle(height, width) {
+//     return Object.create(rectanglePrototypes, {
+//         height: {
+//             value: height,
+//         },
+//         width: {
+//             value: width,
+//         },
+//     });
+// }
+
+// const rect = createRectangle(10, 20);
+// console.log(rect);
+// console.log(rect.area());
+// console.log(rect.isSquare());
+
+// const rect2 = createRectangle(20, 20);
+// console.log(rect2.area());
+
+
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+
+
+// const strLit = 'hello';
+// const strObj = new String('HELLO');
+
+// console.log(strLit, typeof strLit);
+// console.log(strObj, typeof strObj);
+
+// console.log(strLit.toUpperCase());
+// console.log(strLit[0]);
+
+// const funcLit = function(x) {
+//     return x * x;
+// }
+
+// console.log(funcLit, typeof funcLit);
+
+// const funcObj = new Function('x', 'return x * x');
+
+// console.log(funcObj(3));
+
+// const obj1 = {};
+// const obj2 = new Object();
+
+// console.log(obj1, typeof obj1);
+// console.log(obj2, typeof obj2);
+