?? Mastering JavaScript Objects: From Basics to Advanced Techniques! ??

https://basescripts.com/mastering-javascript-objects-from-basics-to-advanced-techniques

Exercise 1: Creating an Object

Problem: Create a JavaScript object named book with properties title, author, and year.

Explanation: This exercise introduces creating a simple object in JavaScript, which is a collection of properties, with each property being a key-value pair.

Code:

let book = {

?title: "1984",

?author: "George Orwell",

?year: 1949

};

Exercise 2: Accessing Object Properties

Problem: Access the author property from the book object and print it to the console.

Explanation: Demonstrates two ways to access properties of an object: dot notation and bracket notation.

Code:

console.log(book.author); // Dot notation

console.log(book['author']); // Bracket notation

Exercise 3: Adding Properties

Problem: Add a new property genre with value "Dystopian" to the book object.

Explanation: Shows how to add new key-value pairs to an existing object.

Code:

book.genre = "Dystopian";

// Or

book['genre'] = "Dystopian";

Exercise 4: Deleting Properties

Problem: Remove the year property from the book object.

Explanation: Demonstrates how to delete a property from an object using the delete operator.

Code:

delete book.year;

Exercise 5: Looping through Object Properties

Problem: Use a for...in loop to print all properties and values of the book object.

Explanation: Shows how to iterate over the keys of an object and access their values.

Code:

for (let key in book) {

?console.log(key + ": " + book[key]);

}

Exercise 6: Checking for Property Existence

Problem: Check whether the book object has a property called author and print "Author exists" if true.

Explanation: Demonstrates how to check if an object has a specific property using the in operator or hasOwnProperty method.

Code:

if ('author' in book) {

?console.log("Author exists");

}

// Or

if (book.hasOwnProperty('author')) {

?console.log("Author exists");

}

Exercise 7: Nested Objects

Problem: Create a user object with properties name (a string), age (a number), and address (an object with properties street, city, and zipcode).

Explanation: Introduces objects within objects, showing how to structure complex data.

Code:

let user = {

?name: "Alice",

?age: 30,

?address: {

?street: "123 Maple St",

?city: "Springfield",

?zipcode: "12345"

?}

};

Exercise 8: Object Methods

Problem: Add a method fullName to the user object that takes firstName and lastName and sets a new fullName property on the user.

Explanation: Shows how to add methods (functions within an object) and use this to refer to the object itself.

Code:

user.fullName = function(firstName, lastName) {

?this.fullName = ${firstName} ${lastName};

};

user.fullName("John", "Doe");

console.log(user.fullName); // Outputs: John Doe

Exercise 9: Object Destructuring

Problem: Given an object employee with properties id, name, and department, use object destructuring to extract and print the name and department.

Explanation: Demonstrates the use of object destructuring, a convenient way to extract multiple properties from an object into variables.

Code:

let employee = {

?id: 1,

?name: "John Doe",

?department: "Finance"

};

let { name, department } = employee;

console.log(name); // John Doe

console.log(department); // Finance

Exercise 10: Merging Objects

Problem: Merge two objects, objectA with properties { a: 1, b: 2 } and objectB with properties { b: 3, c: 4 }, into a new object mergedObject.

Explanation: Explores object merging, particularly how properties from one object can override those of another.

Code:

let objectA = { a: 1, b: 2 };

let objectB = { b: 3, c: 4 };

let mergedObject = { ...objectA, ...objectB };

console.log(mergedObject); // { a: 1, b: 3, c: 4 }